Nocin L

Uses

Bacitracin is a cyclic polypeptide antibiotic used to prevent wound infections, treat pneumonia and empyema in infants, and to treat skin and eye infections.

Bacitracin is indicated in topical formulations for acute and chronic localized skin infections. Occasionally, it is also used intramuscularly for infantile streptococcal pneumonia and empyema. Bacitracin is also formulated as an ointment with neomycin and polymyxin B for over the counter use. A bacitracin ointment formulated with neomycin and polymyxin B along with hydrocortisone is indicated for the treatment of corticosteroid responsive dermatoses with secondary infection.

Lidocaine is a topical anesthetic used for the following purposes-

• To help prevent pain associated with minor surgical procedures in the ear, nose and throat
• To help prevent pain and or discomfort during dental procedures (e.g., prior to an injection)
• During general anesthesia to prevent coughing
• To help prevent pain during the final stages of childbirth, before the cutting or stitching of the perineum (skin between the vagina and anus)

Neomycin is an aminoglycoside antibiotic agent used orally and topically to treat a wide variety of infections in the body.

Oral neomycin sulfate is indicated as an adjunctive therapy in hepatic coma (portal-system encephalopathy) by reducing ammonia-forming bacteria in the intestinal tract. It is strongly recommended that oral neomycin is only used in infections that are proven or strongly suspected to be caused by susceptible bacteria to reduce the risk of the development of drug-resistant bacteria.

Neomycin, in combination with polymyxin B sulfates and hydrocortisone in otic suspensions, is used in the treatment of superficial bacterial infections of the external auditory canal caused by organisms susceptible to the antibiotics. This otic formulation is also used in the treatment of infections of mastoidectomy and fenestration cavities caused by organisms susceptible to the antibiotics.

The ophthalmic solution containing neomycin in combination with polymyxin B sulfates and dexamethasone is used to treat steroid-responsive inflammatory ocular conditions for which a corticosteroid is indicated and where bacterial infection or a risk of bacterial infection exists.

Acute infections caused by susceptible strains of Pseudomonas aeruginosa:

Polymyxin B Sulfate is a drug of choice in the treatment of infections of the urinary tract, meninges, and bloodstream caused by susceptible strains of Pseudomonas aeruginosa.

It may be used for serious infections caused by susceptible strains of the following organisms, when less potentially toxic drugs are ineffective or contraused:

• H. influenzae: Specifically meningeal infections
• Escherichia coli: Specifically urinary tract infections
• Aerobacter aerogenes: Specifically bacteremia
• Klebsiella pneumoniae: Specifically bacteremia

Nocin L is also used to associated treatment for these conditions: Acne, Bacterial Infections of the Intestine, Empyema, Eye Infections, Infected Wound, Infection, Inflammatory Reaction caused by Acne, Ocular Inflammatory Disease, Pneumonia, Skin Ulcer, Corticosteroid-responsive dermatoses, Infection in minor cuts, scrapes, or burns, Wound siteAcute Otitis Media, Anal Fissures, Anorectal discomfort, Arrhythmia, Back Pain Lower Back, Bacterial Vaginosis (BV), Burns, Cervical Syndrome, Earache, Hemorrhoids, Infection, Inflammatory Reaction caused by ear infection-not otherwise specified, Insect Bites, Joint Pain, Mixed Vaginal Infections, Multiple Myeloma (MM), Myringitis, Neuritis, Osteolysis caused by Bone Tumors, Osteoporosis, Otitis Externa, Pain caused by ear infection-not otherwise specified, Pain, Inflammatory, Post-Herpetic Neuralgia (PHN), Postherpetic Neuralgia, Primary Hyperparathyroidism, Rheumatic Diseases, Rheumatic Joint Disease, Sciatica, Skin Irritation, Soft Tissue Inflammation, Sore Throat, Sunburn, Susceptible infections, Trichomonas Vaginitis, Ulcers, Leg, Urethral Strictures, Vulvovaginal Candidiasis, Abrasions, Anal discomfort, Arrhythmia of ventricular origin, Cutaneous lesions, Gum pain, Minor burns, Superficial Wounds, Susceptible Bacterial Infections, Ulceration of the mouth, Viral infections of the external ear canal, Post Myocardial Infarction Treatment, Regional Anesthesia, Local anesthesia therapyAcne pustular, Allergic Contact Dermatitis, Allergy Skin, Atopic Dermatitis (AD), Atopic Dermatitis (AD) of the external ear canal, Bacterial diarrhoea, Burns, Carbuncle, Cradle Cap, Dermatitis, Dermatitis, Contact, Dermatitis, Eczematous, Diarrhoea, Discoid Lupus Erythematosus (DLE), Ear infection bacterial, Ear infection bacterial caused by susceptible bacteria, Gastrointestinal Infections, Hepatic coma, Hidradenitis Suppurativa (HS), Hot Water Burns (Scalds), Impetigo, Impetigo contagious, Infantile Eczema, Infected Wounds, Infected skin ulcer, Infection of the outer ear caused by susceptible bacteria, Infectious diarrhea, Inflammatory Reaction caused by Acne, Intertrigo, Itching caused by Infection, Lichen Planus (LP), Localized Infection caused by susceptible bacteria, Nail infection, Neurodermatitis, Otitis Externa, Postoperative Wound Infection, Psoriasis Vulgaris (Plaque Psoriasis), Pustular Dermatosis, Radiodermatitis, Secondarily Infected Eczema, Secondary Bacterial Infection, Skin Burns, Skin Infections, Skin Infections, Bacterial, Skin Irritation, Skin Ulcer, Solar erythema, Abrasions, Blistering caused by Staphylococcus, Erythematous eruptions, Intertriginous erythema of the anogenital, Ocular bacterial infections caused by susceptible bacteria, Resistant to other corticosteroids Dermatosis, Susceptible Bacterial InfectionsAcute Otitis Media, Bacteremia caused by Enterobacter aerogenes, Bacterial Conjunctivitis, Bacterial Infections, Chronic Otitis Media, Escherichia urinary tract infection, Klebsiella bacteraemia, Meningitis caused by Haemophilus influenzae, Meningitis, Bacterial, Ocular Inflammation, Otitis Externa, Otorrhoea, Superficial ocular infections of the conjunctiva caused by susceptible bacteria, Superficial ocular infections of the cornea caused by susceptible bacteria, Urinary Tract Infection, Ocular bacterial infections

How Nocin L works

Bacitracin binds to a divalent metal ion such as Mn(II), Co(II), Ni(II), Cu(II), or Zn(II). These complexes bind C₅₅-isoprenyl pyrophosphate, preventing the hydrolysis of a lipid dolichol pyrophosphate, which finally inhibits cell wall synthesis. Bacitracin metal complexes also bind and oxidatively cleave DNA.

Lidocaine is a local anesthetic of the amide type . It is used to provide local anesthesia by nerve blockade at various sites in the body . It does so by stabilizing the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby effecting local anesthetic action . In particular, the lidocaine agent acts on sodium ion channels located on the internal surface of nerve cell membranes . At these channels, neutral uncharged lidocaine molecules diffuse through neural sheaths into the axoplasm where they are subsequently ionized by joining with hydrogen ions . The resultant lidocaine cations are then capable of reversibly binding the sodium channels from the inside, keeping them locked in an open state that prevents nerve depolarization . As a result, with sufficient blockage, the membrane of the postsynaptic neuron will ultimately not depolarize and will thus fail to transmit an action potential . This facilitates an anesthetic effect by not merely preventing pain signals from propagating to the brain but by aborting their generation in the first place .

In addition to blocking conduction in nerve axons in the peripheral nervous system, lidocaine has important effects on the central nervous system and cardiovascular system . After absorption, lidocaine may cause stimulation of the CNS followed by depression and in the cardiovascular system, it acts primarily on the myocardium where it may produce decreases in electrical excitability, conduction rate, and force of contraction .

Like other aminoglycoside antibiotic drugs, neomycin inhibits bacterial ribosomes by binding to the 30S ribosomal subunit of susceptible bacteria and disrupting the translational machinery of bacterial protein synthesis. Bacterial translation is normally initiated by the mRNA binding to the 30S ribosomal subunit and subsequent binding with 50S subunit for elongation.

The alpha and gamma diaminobutyric acid of a positively charged polymyxin B forms an electrostatic interaction with the phosphate groups of a negatively charged lipid A on the outer membrane of a Gram negative bacterium. Calcium and Magnesium ions are displaced from phosphates of the membrane lipids, destabalising the lipopolysaccharide (LPS), increasing membrane permeability, causing cytoplasmic leaking, and killing the cell.

Polymyxin B can also bind and neutralize LPS released during bacterial lysis, preventing reactions to endotoxin.

A third activity of polymyxin B is the inhibition of type II NADH-quinone oxidoreductases in the bacterial inner membrane, which are essential for respiration.

Polymyxin is active against common Gram negative bacteria but not Gram negative cocci, Gram positive bacteria, or anaerobic bacteria.

Dosage

Nocin L dosage

Intramuscular:Emergency treatment of ventricular arrhythmias: 300 mg injected into the deltoid muscle, repeat after 60-90 min if necessary.

Intraspinal:Spinal anaesthesia: As hyperbaric soln of 1.5% or 5% lidocaine in 7.5% glucose soln. Normal vaginal delivery: Up to 50 mg (as 5% soln) or 9-15 mg (as 1.5% soln). Caesarian operation: Up to 75 mg (as 5% soln). Other surgical procedures: 75-100 mg.Intravenous:Pulseless ventricular fibrillation or ventricular tachycardia : 1-1.5 mg/kg repeated as necessary. Max: 3 mg/kg. For ventricular arrhythmias in more stable patients: Usual loading dose: 50-100 mg as an IV inj at 25-50 mg/min, may repeat once or twice up to a max of 200-300 mg in 1 hr, followed by 1-4 mg/min via continuous IV infusion. May need to reduce dose if the infusion is longer than 24 hr.

Intravenous:Intravenous regional anaesthesia: As 0.5% soln w/o epinephrine: 50-300 mg. Max: 4 mg/kg.

Parenteral:Percutaneous infiltration anaesthesia: As 0.5% or 1% soln: 5-300 mg.Sympathetic nerve block: As 1% soln: 50 mg for cervical block or 50-100 mg for lumbar block.Peripheral nerve block:

• As 1.5% soln: For brachial plexus block: 225-300 mg.
• As 2% soln: For dental nerve block: 20-100 mg.
• As 1% soln: For intercostal nerve block: 30 mg;
• For paracervical block: 100 mg on each side, repeated not more frequently than every 90 min;
• For paravertebral block: 30-50 mg;
• For pudendal block: 100 mg on each side.
• As 4% soln: For retrobulbar block: 120-200 mg.

Spray:

• The maximum dose is 200 mg (Approximately 20 spray).
• In dentistry, the normal dose is 1-5 sprays. Two sprays per quarter of the mouth is recommended, with a maximum of 3 sprays per quarter of the mouth over 30 minutes.
• In sinus procedures 3 sprays are used.
• In procedures of the throat and windpipe, up to 20 sprays may be necessary.
• Up to 20 sprays may be necessary in childbirth (cesarian procedure).
• Lower doses are used for children aged 3-12 years. Lidocaine 10% Spray is not recommended for children under 3 years.

Topical: Anaesthesia before e.g. venepuncture (not for infants), apply a thick layer under an occlusive dressing 1-5 hours before procedure; split skin grafting, apply a thick layer under an occlusive dressing 2-5 hours before procedure; genital warts (not for children), apply up to 10 gm 5-10 minutes before removal.

Intravenous: Dissolve Polymyxin B 500,000 units in 300 to 500 ml solutions for parenteral Dextrose injection 5% for continuous drip.

Intramuscular: Dissolve Polymyxin B 500,000 units in 2 ml 0.9% Sodium Chloride solution. It is not recommended routinely because of severe pain at injection site, particularly in infants and children.

Intrathecal: Dissolve Polymyxin B 500,000 units in 10 ml 0.9% Sodium Chloride solution for 50,000 units per ml dosage unit.

In meningeal infections, Polymyxin B Sulfate should be administered only by the intrathecal route.

For IV route:

• Adult & Children (Normal kidney function): Dose (Units/kg/day) is 15,000-25,000(Not exceed 25,000) and Dosage frequency/Duration is infusions may be given every 12 hours over a period of approximately 60 to 90 minutes.
• Adult & Children (Renal impairment): Dose (Units/kg/day) is Less than 15,000 and Dosage frequency/Duration is Infusions may be given every 12 hours over a period of approximately 60 to 90 minutes.
• Infants (Normal kidney function): Dose (Units/kg/day) is Maximum 40,000

• Adult & Children: Dose (Units/kg/day) is 25,000-30,000 and Dosage frequency/Duration is Dose should be reduced in the presence of renal impairment. The dosage may be divided and given at either 4 or 6 hour intervals.
• Infants (Normal kidney function): Dose (Units/kg/day) is Maximum 40,000

• Children under 2 years of age: Dosage frequency/Duration is 20,000 units once daily, intrathecally for 3 to 4 days or 25,000 units once every other day. Continue with a dose of 25,000 units once every other day for at least 2 weeks after cultures of the cerebrospinal fluid are negative and sugar content has returned to normal.
• Adults and children over 2 years of age: 50,000 units once daily for 3 to 4 days, then 50,000 units once every other day for at least 2 weeks after cultures of the cerebrospinal fluid are negative and sugar content has returned to normal.

Side Effects

Arrhythmia, bradycardia, arterial spasms, CV collapse, oedema, flushing, hert block, hypotension, sinus node suppression, agitation, anxiety, coma, confusion, drowsiness, hallucinations, euphoria, headache, hyperaesthesia, hypoaesthesia, lightheadedness, lethargy, nervousness, psychosis, seizure, slurred speech, unconsciousness, somnolence, nausea, vomiting, metallic taste, tinnitus, disorientation, dizziness, paraesthesia, resp depression and convulsions. Patch: Bruising, depigmentation, petechiae, irritation. Ophth: Conjunctival hyperaemia, corneal epithelial changes, diplopia,visual changes.

Clostridium difficile associated diarrhea has been reported with use of Polymyxin B. Nephrotixic reactions: Albuminuria, cylinduria, azotemia, and rising blood levels, Neurotoxic reactions: Facial flushing, dizziness progressing to ataxia, drowsiness, peripheral aresthesias (circumoral and stocking glove), apnea due to concurrent use of curariform muscle relaxants, other neurotoxic drugs or inadvertent overdosage, and signs of meningeal irritation with intrathecal administration, e.g., fever, headache, stiff neck. Other reactions occasionally reported: Drug fever, urticaria rash, severe pain at IM injections sites and thrombophelbitis at IV injections sites.

Toxicity

The oral LD₅₀ of bacitracin in rats is >2000mg/kg.

Specific data regarding bacitracin overdoses is not readily available. An overdose of bacitracin may lead to nephrotoxicity and patients should be treated with supportive measures.

Symptoms of overdose and/or acute systemic toxicity involves central nervous system toxicity that presents with symptoms of increasing severity . Patients may present initially with circumoral paraesthesia, numbness of the tongue, light-headedness, hyperacusis, and tinnitus . Visual disturbance and muscular tremors or muscle twitching are more serious and precede the onset of generalized convulsions . These signs must not be mistaken for neurotic behavior . Unconsciousness and grand mal convulsions may follow, which may last from a few seconds to several minutes . Hypoxia and hypercapnia occur rapidly following convulsions due to increased muscular activity, together with the interference with normal respiration and loss of the airway . In severe cases, apnoea may occur. Acidosis increases the toxic effects of local anesthetics . Effects on the cardiovascular system may be seen in severe cases . Hypotension, bradycardia, arrhythmia and cardiac arrest may occur as a result of high systemic concentrations, with potentially fatal outcome .

Pregnancy Category B has been established for the use of lidocaine in pregnancy, although there are no formal, adequate, and well-controlled studies in pregnant women . General consideration should be given to this fact before administering lidocaine to women of childbearing potential, especially during early pregnancy when maximum organogenesis takes place . Ultimately, although animal studies have revealed no evidence of harm to the fetus, lidocaine should not be administered during early pregnancy unless the benefits are considered to outweigh the risks . Lidocaine readily crosses the placental barrier after epidural or intravenous administration to the mother . The ratio of umbilical to maternal venous concentration is 0.5 to 0.6 . The fetus appears to be capable of metabolizing lidocaine at term . The elimination half-life in the newborn of the drug received in utero is about three hours, compared with 100 minutes in the adult . Elevated lidocaine levels may persist in the newborn for at least 48 hours after delivery . Fetal bradycardia or tachycardia, neonatal bradycardia, hypotonia or respiratory depression may occur .

Local anesthetics rapidly cross the placenta and when used for epidural, paracervical, pudendal or caudal block anesthesia, can cause varying degrees of maternal, fetal and neonatal toxicity . The potential for toxicity depends upon the procedure performed, the type and amount of drug used, and the technique of drug administration . Adverse reactions in the parturient, fetus and neonate involve alterations of the central nervous system, peripheral vascular tone, and cardiac function .

Maternal hypotension has resulted from regional anesthesia . Local anesthetics produce vasodilation by blocking sympathetic nerves . Elevating the patient’s legs and positioning her on her left side will help prevent decreases in blood pressure . The fetal heart rate also should be monitored continuously, and electronic fetal monitoring is highly advisable .

Epidural, spinal, paracervical, or pudendal anesthesia may alter the forces of parturition through changes in uterine contractility or maternal expulsive efforts . In one study, paracervical block anesthesia was associated with a decrease in the mean duration of first stage labor and facilitation of cervical dilation . However, spinal and epidural anesthesia have also been reported to prolong the second stage of labor by removing the parturient’s reflex urge to bear down or by interfering with motor function . The use of obstetrical anesthesia may increase the need for forceps assistance .

The use of some local anesthetic drug products during labor and delivery may be followed by diminished muscle strength and tone for the first day or two of life . The long-term significance of these observations is unknown . Fetal bradycardia may occur in 20 to 30 percent of patients receiving paracervical nerve block anesthesia with the amide-type local anesthetics and may be associated with fetal acidosis . Fetal heart rate should always be monitored during paracervical anesthesia . The physician should weigh the possible advantages against risks when considering a paracervical block in prematurity, toxemia of pregnancy, and fetal distress . Careful adherence to the recommended dosage is of the utmost importance in obstetrical paracervical block . Failure to achieve adequate analgesia with recommended doses should arouse suspicion of intravascular or fetal intracranial injection . Cases compatible with unintended fetal intracranial injection of local anesthetic solution have been reported following intended paracervical or pudendal block or both. Babies so affected present with unexplained neonatal depression at birth, which correlates with high local anesthetic serum levels, and often manifest seizures within six hours . Prompt use of supportive measures combined with forced urinary excretion of the local anesthetic has been used successfully to manage this complication .

It is not known whether this drug is excreted in human milk . Because many drugs are excreted in human milk, caution should be exercised when lidocaine is administered to a nursing woman .

Dosages in children should be reduced, commensurate with age, body weight and physical condition .

The oral LD 50 of lidocaine HCl in non-fasted female rats is 459 (346-773) mg/kg (as the salt) and 214 (159-324) mg/kg (as the salt) in fasted female rats .

The oral LD₅₀ of neomycin sulfate in mouse is > 8 g/kg. The subcutaneous LD₅₀ is 200 mg/kg in rat and 190 mg/kg in mouse. The intraperitoneal LD₅₀ in mouse is 305 mg/kg. The oral Lowest published toxic dose (TDLo) in woman is 12600 mg/kg/7D.

Because of low absorption, acute overdosage from oral neomycin is not likely to occur. However, prolonged administration of neomycin should be avoided because of the possibility of some systemic absorption and the risk of neurotoxicity, ototoxicity, and/or nephrotoxicity. Hemodialysis will remove neomycin from the blood. While nephrotoxicity and ototoxicity have been reported in otherwise patients without compromised renal function, the risk for developing these toxicities is increased in patients with renal impairment. Like other aminoglycosides, neomycin may cause fetal harm and total irreversible bilateral congenital deafness when administered in pregnant women.

Nephrotoxicity can occur in patients as polymyxin B is thought to accumulate in renal cells after renal tubular reabsorption. This accumulation can lead to apoptosis of renal cells and decrease in renal function. In recent studies, acute kidney injury (AKI) has been seen in 31.3% to 39.4% of patients receiving polymyxin B.

Overdose cases can cause neuromuscular block leading to apnea, muscular weakness, vertigo, transient facial parasthesia, slurred speed, vasomotor instability, visual disturbance, confusion, psychosis, and respiratory arrest. Renal failure has also been seen through decreased urine output, and increased serum concentrations of blood urea nitrogen.

Overdose of polymyxin B is treated by stopping the drug and beginning symptomatic treatment. Intravenous administration of mannitol may enhance renal clearance, and hemodialysis may manage renal complications.

Safety of polymyxin B has not been established in pregnancy, breast feeding, pediatrics, and geriatrics. Polymyxin B should no be used in pregnancy unless the benefit outweighs the risk. Nursing mothers should either stop nursing or stop polymyxin B treatment depending on the risks to both the mother and child. Pediatric patients should be frequently monitored for renal function and no dosing information is available in children under 2 years of age. Geriatric patients should have renal function assessed before and regularly during therapy.

Precaution

Patient with pseudocholinesterase deficiency, resp depression. Hepatic and renal impairment. Elderly or debilitated patients. Pregnancy and lactation.

Baseline renal function should be done prior to therapy, with frequent monitoring of renal function and blood levels of the drug during parenteral therapy.

Interaction

May increase serum levels with cimetidine and propranolol. Increased risk of cardiac depression with β-blockers and other antiarrhythmics. Additive cardiac effects with IV phenytoin. Hypokalaemia caused by acetazolamide, loop diuretics and thiazides may antagonise effect of lidocaine. Dose requirements may be increased with long-term use of phenytoin and other enzyme-inducers.

The concurrent or sequential use of other neurotoxic and/or nephrotox-ic drugs with Polymyxin B sulfate, particularly bacitracin, kanamycin, streptomycin, tobramycin, amikacin, cephaloridine, cephalothin, paromycin, polymyxin E (colistin), neomycin, gentamicin, and vancomycin, Bumetanide, celecoxib, cisplatin, cyclosporine, diclofenac, misoprostol, diphenhydramine, ibuprofen, naproxen, esomeprazole, etodolac, general anesthetic, gentamycin, ketorolac, meloxicam, tenofovir etc should be avoided.

Volume of Distribution

Data regarding the volume of distribution of bacitracin in humans is not readily available.

The volume of distribution determined for lidocaine is 0.7 to 1.5 L/kg .

In particular, lidocaine is distributed throughout the total body water . Its rate of disappearance from the blood can be described by a two or possibly even three-compartment model . There is a rapid disappearance (alpha phase) which is believed to be related to uptake by rapidly equilibrating tissues (tissues with high vascular perfusion, for example) . The slower phase is related to distribution to slowly equilibrating tissues (beta phase) and to its metabolism and excretion (gamma phase) .

Lidocaine's distribution is ultimately throughout all body tissues . In general, the more highly perfused organs will show higher concentrations of the agent . The highest percentage of this drug will be found in skeletal muscle, mainly due to the mass of muscle rather than an affinity .

The small fraction of absorbed neomycin is rapidly distributed in the tissues. The amount of systemically absorbed neomycin is reported to increase cumulatively with each repeated dose administered until a steady state is reached.

1 compartment models estimate the volume of distribution to be 34.3L to 47.2L. However, the general consensus is that the volume of distribution is yet to be determined.

Elimination Route

Topical, ophthalmic, and oral formulations of bacitracin are poorly absorbed systemically. Intramuscular bacitracin is readily and completely absorbed.

In general, lidocaine is readily absorbed across mucous membranes and damaged skin but poorly through intact skin . The agent is quickly absorbed from the upper airway, tracheobronchial tree, and alveoli into the bloodstream . And although lidocaine is also well absorbed across the gastrointestinal tract the oral bioavailability is only about 35% as a result of a high degree of first-pass metabolism . After injection into tissues, lidocaine is also rapidly absorbed and the absorption rate is affected by both vascularity and the presence of tissue and fat capable of binding lidocaine in the particular tissues .

The concentration of lidocaine in the blood is subsequently affected by a variety of aspects, including its rate of absorption from the site of injection, the rate of tissue distribution, and the rate of metabolism and excretion . Subsequently, the systemic absorption of lidocaine is determined by the site of injection, the dosage given, and its pharmacological profile . The maximum blood concentration occurs following intercostal nerve blockade followed in order of decreasing concentration, the lumbar epidural space, brachial plexus site, and subcutaneous tissue . The total dose injected regardless of the site is the primary determinant of the absorption rate and blood levels achieved . There is a linear relationship between the amount of lidocaine injected and the resultant peak anesthetic blood levels .

Nevertheless, it has been observed that lidocaine hydrochloride is completely absorbed following parenteral administration, its rate of absorption depending also on lipid solubility and the presence or absence of a vasoconstrictor agent . Except for intravascular administration, the highest blood levels are obtained following intercostal nerve block and the lowest after subcutaneous administration .

Additionally, lidocaine crosses the blood-brain and placental barriers, presumably by passive diffusion .

Neomycin is poorly absorbed from the gastrointestinal tract. Gastrointestinal absorption of the drug may be increased if inflammatory or ulcerative gastrointestinal disease is present.

Administration by the oral route does not lead to absorption.

Half Life

Data regarding the half life of bacitracin in humans is not readily available.

The elimination half-life of lidocaine hydrochloride following an intravenous bolus injection is typically 1.5 to 2.0 hours . Because of the rapid rate at which lidocaine hydrochloride is metabolized, any condition that affects liver function may alter lidocaine HCl kinetics . The half-life may be prolonged two-fold or more in patients with liver dysfunction .

There is limited information on the half-life of neomycin.

In one study the half life was 9 to 11.5 hours. However, a Canadian monograph states the half life to be 6 hours, and 48-72 hours in patients with renal insufficiency.

Clearance

Data regarding the clearance of bacitracin in humans has not been well studied. A study of 9 subjects in 1947 shows a renal clearance of 105-283mL/min with an average renal clearance of 159mL/min.

The mean systemic clearance observed for intravenously administered lidocaine in a study of 15 adults was approximately 0.64 +/- 0.18 L/min .

There is limited information on the clearance rate of neomycin.

1 compartment models estimate clearance to be 2.37L/h to 2.5L/h.

Elimination Route

Bacitracin is mainly excreted renally with 87% of and intramuscular dose being recovered in the urine after 6 hours.

The excretion of unchanged lidocaine and its metabolites occurs predominantly via the kidney with less than 5% in the unchanged form appearing in the urine . The renal clearance is inversely related to its protein binding affinity and the pH of the urine . This suggests by the latter that excretion of lidocaine occurs by non-ionic diffusion .

The small absorbed fraction of neomycin is excreted by the kidney. The unabsorbed portion of the drug is excreted unchanged in the feces.

Polymyxin B is proposed to be primarily eliminated through renal tubular reabsorption and non-renal pathways. Urine collection in humans and animals show 1. However, a Canadian product monograph states the drug is primarily eliminated through the kidneys and that 60% of polymyxin B is recovered in the urine. This discrepancy can be explained by the 12 to 24 hour lag time between administration and significant elimination of polymyxin B. Non-renal elimination is not well understood but all 4 components of polymyxin B have been detected in bile.

Pregnancy & Breastfeeding use

Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

There are no controlled data in human pregnancy. Safety has not been established during pregnancy. There is no recommendation regarding use during lactation. There is no study on whether it is secreted with human milk.

Contraindication

Hypovolaemia, complete heart block, Adam-Stokes syndrome, Wolff-Parkinson-White syndrome. Must not be applied to inflamed or injured skin.

Special Warning

Hepatic Impairment Parenteral: Dosage reduction may be needed.

Acute Overdose

Symptoms: Severe hypotension, asystole, bradycardia, apnoea, seizures, coma, cardiac arrest, resp arrest and death.

Management: Maintain oxygenation, stop convulsion and support the circulation.

Polymyxin-induced toxicity associated with overdose has been reported. Overdose of Polymyxin can result in neuromuscular blockade, which can lead to apnea, muscular weakness, vertigo, transient facial paresthesia, slurred speech, vasomotor instability, visual disturbance, confusion, psychosis and possible respiratory arrest. Overdose can also cause renal failure characterized by decreased urine output and increased serum concentrations of BUN and creatinine. There is no specific antidote for Polymyxin B Sulfate overdose. In case of Polymyxin B Sulfate overdose, the drug should be stopped and symptomatic treatment instituted. Quick diuresis by IV administered mannitol may help to enhance renal clearance of the drug and thus to reduce serum drug levels. Hemodialysis or peritoneal dialysis may help in order to manage renal complications.

Storage Condition

Store below 25°C.

Before reconstitution, do not store above 30°C; and keep away from light and out of the reach of children. After reconstitution or dilution, unused portion must be stored at 2° to 8°C and should be discarded after 72 hours if not used.

Innovators Monograph

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