Capxib

Capxib Uses, Dosage, Side Effects, Food Interaction and all others data.

Although the precise mechanism of action of Capsaicin is not fully understood, current evidence suggests that Capsaicin exerts an analgesic effect by depleting and preventing reaccumulation of Substance P in peripheral sensory neurons. Substance P is thought to be the principal chemomediator of pain impulses from the periphery to the central nervous system.

Capsaicin is a TRPV1 receptor agonist. TRPV1 is a trans-membrane receptor-ion channel complex activated by temperatures higher than 43 degrees Celsius, pH lower than 6, and endogenous lipids. When activated by a combination of these factors, the channel can transiently open and initiate depolarization due to the influx of calcium and sodium ions. Because TRPV1 is commonly expressed in A-delta and mostly C fibers, depolarization results in action potentials which send impulses to the brain and spinal cord. These impulses result in capsaicin effects of warming, tingling, itching, stinging, or burning. Capsaicin also causes more persistent activation of these receptors compared to the environmental agonists, resulting in a loss of response to many sensory stimuli, described as "defunctionalization". Capsaicin is associated with many enzymatic, cytoskeletal, and osmotic changes, as well as disruption of mitochondrial respiration, impairing nociceptor function for extended periods of time.

Celecoxib is a nonsteroidal anti-inflammatory drug that exhibits anti-inflammatory, analgesic and antipyretic activities. The mechanism of action of Celecoxib is believed to be due to inhibition of prostaglandin synthesis, primarily via inhibition of cyclooxygenase-2 (COX-2) and at therapeutic concentrations in humans, Celecoxib does not inhibit the cyclooxygenase-1 (COX-1) isoenzyme.

Celecoxib inhibits cyclooxygenase 2 (COX-2) enzyme, reducing pain and inflammation. It is important to note that though the risk of bleeding with celecoxib is lower than with certain other NSAIDS, it exists nonetheless and caution must be observed when it is administered to those with a high risk of gastrointestinal bleeding.

A note on the risk of cardiovascular events

Significant concerns regarding the safety of COX-2 selective NSAIDs emerged in the early 2000s. Rofecoxib, another member of the COX-2 inhibitor drug class, also known as Vioxx, was withdrawn from the market due to prothrombotic cardiovascular risks. Following an FDA Advisory Committee meeting in 2005, in which data from large clinical outcome trials were evaluated, the FDA concluded that the risk for cardiovascular thrombotic events for both COX-2 selective NSAIDs and nonselective NSAIDs was evident. It was determined that the benefits of celecoxib treatment, however, outweighed the risks. Postmarketing cardiovascular outcomes trial (PRECISION) revealed that the lowest possible dose of celecoxib was similar in cardiovascular safety to moderate strength doses of both naproxen and ibuprofen. Patients who had previous cardiovascular events including acute MI, coronary revascularization, or coronary stent insertion were not evaluated in the trial. It is not advisable to administer NSAIDS to these groups of patients.

Capxib
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Capxib
Generic	Celecoxib + menthol + capsaicin
Type	Kit
Therapeutic Class
Manufacturer
Available Country	United States
Last Updated:	September 19, 2023 at 7:00 am

Uses

Capsaicin is indicatd for- Rheumatoid arthritis, Osteoarthritis, Pain due to diabetic neuropathy, Joint pain, Post-herpetic neuralgia, Post-surgical neuropathic pain, Nerve Pain, Back pain, Muscle pain, Fibromyalgia, Bursitis, Pruritis (itching)

Celecoxib used for relief of the signs and symptoms of osteoarthritis, for relief of the signs and symptoms of rheumatoid arthritis; for relief of pain after dental extraction; for reduction of colorectal polyps in Familial Adenomatous Polyposis (FAP)

Capxib is also used to associated treatment for these conditions: Arthritis, Back Pain Lower Back, Backache, Bursitis, Contusions, Inflammatory Reaction caused by Rheumatism, Muscle Cramps, Musculoskeletal Pain, Osteoarthritis (OA), Periarthritis, Post-Herpetic Neuralgia (PHN), Rheumatic Pain, Soft Tissue Injury, Tendinitis, Acute nonspecific tenosynovitisAnkylosing Spondylitis (AS), Osteoarthritis (OA), Pain, Acute, Primary Dysmenorrhoea, Rheumatoid Arthritis, Rheumatoid Arthritis, Juvenile

How Capxib works

Capsaicin has been shown to reduce the amount of substance P associated with inflammation - however this is not believed to be its main mechanism in the relief of pain . Capsaicin's mechanism of action is attributed to "defunctionalization" of nociceptor fibers by inducing a topical hypersensitivity reaction on the skin. This alteration in pain mechanisms is due to many of the following: temporary loss of membrane potential, inability to transport neurotrophic factors leading to altered phenotype, and reversible retraction of epidermal and dermal nerve fiber terminals.

Unlike most NSAIDs, which inhibit both types of cyclooxygenases (COX-1 and COX-2), celecoxib is a selective noncompetitive inhibitor of cyclooxygenase-2 (COX-2) enzyme. COX-2 is expressed heavily in inflamed tissues where it is induced by inflammatory mediators. The inhibition of this enzyme reduces the synthesis of metabolites that include prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane (TXA2), prostaglandin D2 (PGD2), and prostaglandin F2 (PGF2). Resultant inhibition of these mediators leads to the alleviation of pain and inflammation.

By inhibiting prostaglandin synthesis, non-steroidal anti-inflammatory drugs (NSAIDs) cause mucosal damage, ulceration and ulcer complication throughout the gastrointestinal tract. Celecoxib poses less of an ulceration risk than other NSAIDS, owing to its decreased effect on gastric mucosal prostaglandin synthesis when compared to placebo.

Celecoxib exerts anticancer effects by binding to the cadherin-11 (CDH11)protein, which is thought to be involved in the progression of tumors, and inhibiting the 3-phosphoinositide-dependent kinase-1 (PDK-1) signaling mechanism. In addition, celecoxib has been found to inhibit carbonic anhydrase enzymes 2 and 3, further enhancing its anticancer effects.

As mentioned in the pharmacodynamics section of this drug entry, celecoxib may cause an increased risk of thrombotic events. The risk of thrombosis resulting from COX-2 inhibition is caused by the vasoconstricting actions of thromboxane A2, leading to enhanced platelet aggregation, which is uncontrolled when the actions of prostacyclin, a platelet aggregation inhibitor, are suppressed through the inhibition of COX-2.

Dosage

Capxib dosage

18 years of age and older:Apply a thin film of Capsaicin cream to affected area 3 to 4 times daily. A burning sensation may occur upon application, but generally disappears with regular use. Application schedules of 3 to 4 times a day for 2 weeks provides optimum pain relief.

Osteoarthritis: The recommended oral dose is 200 mg per day administered as a single dose or as 100 mg twice daily.

Rheumatoid arthritis: The recommended oral dose is 100 to 200 mg twice daily.

Familial adenomatous polyposis (FAP): The recommended oral dose is 400 mg twice daily to be taken with food.

Dental pain: Single dose of Celecoxib 100 mg to400 mg

Side Effects

Capsaicin may cause transient burning on application. This burning is observed more frequently when the application schedules are more than 3-4 times daily. The burning can be enhanced if too much cream is used and if it is applied just before or after a bath or shower.

Gastrointestinal side effects include abdominal pain, diarrhoea, dyspepsia, flatulence and nausea. Central nervous system side effects include dizziness, headache and insomnia. Other side effects include upper respiratory tract infection, skin rash, back pain and peripheral edema.

Toxicity

Acute oral LD50 and dermal LD50 in mouse are 47.2 mg/kg and >512 mg/kg, respectively . Capsaicin is shown to be mutagenic for bacteria and yeast .

Capsaicin can cause serious irritation, conjunctivitis and lacrimation via contact with eyes. It induces a burning sensation and pain in case of contact with eyes and skin. As it is also irritating to the respiratory system, it causes lung irritation and coughing as well as bronchoconstriction. Other respiratory effects include laryngospasm, swelling of the larynx and lungs, chemical pneumonitis,respiratory arrest and central nervous system effects such as convulsions and excitement . In case of ingestion, gastrointestinal tract irritation may be observed along with a sensation of warmth or painful burning . Symptoms of systemic toxicity include disorientation, fear, loss of body motor control including diminished hand-eye coordination, hyperventilation, tachycardia, and pulmonary oedema . Careful early decontamination is recommended and medical intervention should be initiated for any life-threatening symptoms. In case of contact, individual must be removed from the source of exposure and the contacted skin and mucous membranes should be thoroughly washed with copious amounts of water .

The oral TDLo in humans 5.71 mg/kg.

It is not advisable to administer celecoxib in patients with renal impairment or advanced hepatic impairment, as this may lead to increased serum concentrations, causing toxicity. Symptoms of overdose may include breathing difficulties, coma, drowsiness, gastrointestinal bleeding, high blood pressure, kidney failure, nausea, sluggishness, stomach pain, and vomiting. Because serious gastrointestinal tract ulceration and bleeding can occur without preceding symptoms, patients should be monitored for signs/symptoms of gastrointestinal bleeding. Symptomatic and supportive measures should be taken in a celecoxib overdose. The induction of emesis or administration of active charcoal should take place if the patient is seen within 4 hours of celecoxib ingestion. Diuresis, urinary alkalinization, hemodialysis, or hemoperfusion may not be useful in a celecoxib overdose due to its high level of protein binding.

Precaution

Capsaicin cream should not be applied to broken or irritated skin. Applied area should not be tightly bandaged. Do not get on mucous membranes and into eyes or on contact lenses. If this occurs, rinse the affected area thoroughly with water. Do not apply the cream on the heat treated area as this may increase the burning sensation. In case of accidental ingestion, seek physician advice immediately.

Celecoxib cannot be expected to substitute for corticosteroids or to treat corticosteroid insufficiency. Patients on prolonged corticosteroid therapy should have their therapy tapered slowly if a decision is made to discontinue corticosteroids. Celecoxib should be prescribed with extreme caution in patients with a prior history of G.I. ulcer-disease or G.I. bleeding, hepatic and renal insufficiency, heart failure, those taking diuretics and ACE inhibitors, pre-existing asthma, elderly patients.

Interaction

Furosemide: NSAIDs can reduce the matriuretic effect of furosemide and thiazides in some patients.

Fluconazole: Concomitant administration of fluconazole at 200 mg QD resulted in a two-fold increase in celecoxib plasma concentration.

Warfarin: Caution should be exercised when administering Celecoxib with warfarin since these patients are at increased risk of bleeding complications.

Volume of Distribution

The apparent volume of distribution of celecoxib at steady state (Vss/F) is about 429 L, which suggests wide distribution into various tissues. Celecoxib is not preferentially bound to red blood cells. Another resource reports a volume of distribution of 455 ± 166L.

Elimination Route

Oral: Following oral administration, capsaicin may be absorbed by a nonactive process from the stomach and whole intestine with an extent of absorption ranging between 50 and 90%, depending on the animal . The peak blood concentration can be reached within 1 hour following administration . Capsaicin may undergo minor metabolism in the small intestine epithelial cells post-absorption from the stomach into the small intestines. While oral pharmacokinetics information in humans is limited, ingestion of equipotent dose of 26.6 mg of pure capsaicin, capsaicin was detected in the plasma after 10 minutes and the peak plasma concentration of 2.47 ± 0.13 ng/ml was reached at 47.1 ± 2.0 minutes .

Systemic: Following intravenous or subcutaneous administration in animals, the concentrations in the brain and spinal cord were approximately 5-fold higher than that in blood and the concentration in the liver was approximately 3-fold higher than that in blood .

Topical: Topical capsaicin in humans is rapidly and well absorbed through the skin, however systemic absorption following topical or transdermal administration is unlikely . For patients receiving the topical patch containing 179 mg of capsaicin, a population analysis was performed and plasma concentrations of capsaicin were fitted using a one-compartment model with first-order absorption and linear elimination. The mean peak plasma concentration was 1.86 ng/mL but the maximum value observed in any patient was 17.8 ng/mL .

Celecoxib is absorbed rapidly in the gastrointestinal tract. When a single oral dose of 200 mg was given to healthy research subjects, the peak plasma levels of celecoxib occurred within 3 hours. The Cmax is 705 ng/mL. When multiple doses are given, steady-state concentrations are reached on or before day 5. When taken with a high-fat meal, peak plasma levels are delayed for about 1 to 2 hours with an increase in total absorption (AUC) of 10% to 20%. The AUC of celecoxib has been shown to be significantly lower in patients with chronic renal impairment. A meta-analysis of pharmacokinetic studies has suggested an approximately 40% higher AUC (area under the curve) of celecoxib in black patients compared to Caucasians for unknown reasons.

Half Life

Following oral ingestion of equipotent dose of 26.6 mg of pure capsaicin, the half life was approximately 24.9 ± 5.0 min . Following topical application of 3% solution of capsaicin, the half-life of capsaicin was approximately 24 h . The mean population elimination half-life was 1.64 h following application of a topical patch containing 179 mg of capsaicin .

The effective half-life of celecoxib is approximately 11 hours when a single 200 mg dose is given to healthy subjects. The terminal half-life of celecoxib varies because of its low solubility, which prolongs absorption.

Clearance

Apparent clearance (CL/F), single oral 200 mg dose, healthy subjects = 27.7 L/hr. Clearance may be decreased by about 47% in patients with chronic renal insufficiency, according to a pharmacokinetic study. Studies have not been performed in patients with severe renal impairment.

Elimination Route

It is proposed that capsaicin mainly undergoes renal excretion, as both the unchanged and glucuronide form. A small fraction of unchanged compound is excreted in the feces and urine. In vivo animal studies demonstrates that less than 10 % of an administered dose was found in faces after 48 h .

Celecoxib is primarily eliminated by hepatic metabolism with small amounts (12 About 57% of an oral dose of celecoxib is excreted in the feces and 27% is found to be excreted into the urine in the form of metabolites. The main metabolite in urine and feces is identified as the carboxylic acid metabolite (73%). The amount of glucuronide in the urine is reported to be low.

Pregnancy & Breastfeeding use

The safety of Capsaicin during pregnancy or lactation has not been established in either humans or animals.

Celecoxib should be used during pregnancy only if the potential benefit justifies the potential risk to fetus. But in late pregnancy Celecoxib should be avoided because it may cause premature closure of ductus arteriosus.

It is not known whether Celecoxib is excreted in human milk. Because many drugs are excreted in human milk and because of potential for serious adverse reactions in nursing infants from Celecoxib, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Contraindication

Capsaicin cream is contraindicated on broken or irritated skin. It is also contraindicated in patients with known hypersensitivity to capsaicin or any of the excipients used in this product.

Celecoxib is contraindicated in patients with known hypersensitivity to Celecoxib, who have demonstrated allergic type reactions to sulfonamide or who have experienced asthma, urticaria or allergic type reactions after taking aspirin or other NSAIDs.

Special Warning

Geriatric: Dose adjustment in the elderly is not generally necessary. However, for patients of less than 50 kg in body weight, initiate therapy at the lowest recommended dose.

Paediatric: The safety and efficacy of Celecoxib is not established in paediatric patients.

Hepatic insufficiency: Celecoxib should be introduced at a reduced dose in patients with moderate hepatic impairment. The use of Celecoxib in patients with severe hepatic impairment is not recommended.