Diphenhydramine And Ibuprofen

Uses

Diphenhydramine is used for the treatment of followings:

• Seasonal, perennial, vasomotor rhinitis
• Urticaria, angioneurotic oedema, anaphylaxis
• Pruiritic conditions
• Premedication for emesis and motion sickness
• Miscellaneous like meniere's disease and parkinsonism

Ibuprofen is used

• For the treatment of sign and symptoms of rheumatoid arthritis, ankylosing spondylitis, osteoarthritis and other non-rheumatoid arthropathies,
• For the treatment of non-articular rheumatic conditions, such as frozen shoulder, bursitis, tendinitis, tenosynovitis and low back pain,
• For the treatment of soft tissue injuries such as sprain, strain and post operative pain
• For the treatment of dysmenorrhoea,
• For the treatment of dental pain.
• For the treatment of cold & fever.

Diphenhydramine And Ibuprofen is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Allergic cough, Allergies, Anaphylaxis, Angioedema, Common Cold, Common Cold/Flu, Conjunctival irritation, Cough, Cough Variant Asthma, Cough caused by Common Cold, Eye allergy, Fever, Insect Bites, Insect Stings, Insomnia, Irritative cough, Itching of the nose, Itching of the throat, Motion Sickness, Nasal Congestion, Oral Mucositis, Pain, Parkinsonian Syndromes, Pollen Allergy, Productive cough, Pruritus, Rash, Rhinorrhoea, Sinus Congestion, Sinus headache, Skin Irritation, Sneezing, Sunburn, Symptoms of Acute Bronchitis Accompanied by Coughing, Upper respiratory tract hypersensitivity reaction, site unspecified, Urticaria, Dermatographism, Dry cough, Watery itchy eyes, Airway secretion clearance therapy, ExpectorantAnkylosing Spondylitis (AS), Common Cold, Cystic Fibrosis (CF), Fever, Gastric Ulcer, Gouty Arthritis, Headache, Insomnia, Juvenile Idiopathic Arthritis (JIA), Menstrual Distress (Dysmenorrhea), Migraine, Mild pain, Nasal Congestion, Osteoarthritis (OA), Pain, Pain, Acute, Pain, Inflammatory, Patent Ductus Arteriosus (PDA), Pericarditis, Primary Dysmenorrhoea, Rheumatoid Arthritis, Severe Pain, Sinus pressure, Mild to moderate pain, Minor aches and pains, Moderate Pain

How Diphenhydramine And Ibuprofen works

Diphenhydramine predominantly works via the antagonism of H1 (Histamine 1) receptors . Such H1 receptors are located on respiratory smooth muscles, vascular endothelial cells, the gastrointestinal tract (GIT), cardiac tissue, immune cells, the uterus, and the central nervous system (CNS) neurons . When the H1 receptor is stimulated in these tissues it produces a variety of actions including increased vascular permeability, promotion of vasodilation causing flushing, decreased atrioventricular (AV) node conduction time, stimulation of sensory nerves of airways producing coughing, smooth muscle contraction of bronchi and the GIT, and eosinophilic chemotaxis that promotes the allergic immune response .

Ultimately, diphenhydramine functions as an inverse agonist at H1 receptors, and subsequently reverses effects of histamine on capillaries, reducing allergic reaction symptoms . Moreover, since diphenhydramine is a first-generation antihistamine, it readily crosses the blood-brain barrier and inversely agonizes the H1 CNS receptors, resulting in drowsiness, and suppressing the medullary cough center .

Furthermore, H1 receptors are similar to muscarinic receptors . Consequently, diphenhydramine also acts as an antimuscarinic . It does so by behaving as a competitive antagonist of muscarinic acetylcholine receptors, resulting in its use as an antiparkinson medication .

Lastly, diphenhydramine has also demonstrated activity as an intracellular sodium channel blocker, resulting in possible local anesthetic properties .

The exact mechanism of action of ibuprofen is unknown. However, ibuprofen is considered an NSAID and thus it is a non-selective inhibitor of cyclooxygenase, which is an enzyme involved in prostaglandin (mediators of pain and fever) and thromboxane (stimulators of blood clotting) synthesis via the arachidonic acid pathway.

Ibuprofen is a non-selective COX inhibitor and hence, it inhibits the activity of both COX-1 and COX-2. The inhibition of COX-2 activity decreases the synthesis of prostaglandins involved in mediating inflammation, pain, fever, and swelling while the inhibition of COX-1 is thought to cause some of the side effects of ibuprofen including GI ulceration.

Dosage

Diphenhydramine And Ibuprofen dosage

Adult-

• Most allergic conditions: 25-50 mg three times a day with a further 50 mg at night.

Children-

• 1 to 5 years of age: 5 mg i.e., 2.5 ml of elixir 4 times a day
• More than 6 years of age: 10 mg i.e. 5 ml of elixir 4 times a day

Oral Administrations-

For Children:

• 20 mg per kg body weight daily in divided doses. In children weighing less than 30 kg the total daily dosage should not exceed 500 mg. If gastrointestinal disturbances occur Ibuprofenshould be given with food or milk.
• 1-2 years: 1/2 tea spoonful (2.5 ml) 3-4 times daily;
• 3-7 years: 1 tea spoonful (5 ml) 3-4 times daily;
• 8-12 years: 2 tea spoonful (10 ml) 3-4 times daily. Ibuprofenis not recommended for children under 1 year.

For adult:

• For arthritic pain: The dosage range is from 0.9 to 2.4 g per day. The usual dose is 400 mg, 3-4 times per day, preferably after food. The dose may be raised to a maximum of 2.4 g daily depending on the severity of symptom at the time of initiating drug therapy or as patients fail to respond. After a satisfactory response has been achieved the patients dose should be reviewed and adjusted as required and tapered gradually.
• For mild to moderate pain: 400 mg 6 hourly or as demanded by the condition.
• For dysmenorrhoea: 400 mg every 4 hours or as demanded by the condition.

Topical Administrations-

Pain and inflammation associated with musculoskeletal and joint disorder: As 5% cream, foam, gel, spray soln or 10% gel: Apply onto affected area.

Side Effects

Side effect includes sedation, dizziness, tinnitus, fatigue, ataxia, blurred vision, diplopia, euphoria, and epigastric discomfort.

Usually Ibuprofen has a low incidence of side effects. The most frequent side effects are gastrointestinal disturbances. Peptic ulceration and gastrointestinal bleeding have occasionally been reported. Other side effects include headache, dizziness, nervousness, skin rash, pruritus, drowsiness, insomnia, blurred vision and other ocular reactions, hypersensitivity reaction, abnormal liver function test, impairment of renal function, agranulocytosis and thrombocytopenia.

Toxicity

Overdose is expected to result in effects similar to the adverse effects that are ordinarily associated with the use of diphenhydramine, including drowsiness, hyperpyrexia, and anticholinergic effects, among others . Additional symptoms during overdose may include mydriasis, fever, flushing, agitation, tremor, dystonic reactions, hallucinations and ECG changes . Large overdose may cause rhabdomyolysis, convulsions, delirium, toxic psychosis, arrhythmias, coma and cardiovascular collapse . Moreover, with higher doses, and particularly in children, symptoms of CNS excitation including hallucinations and convulsions may appear; with massive doses, coma or cardiovascular collapse may follow .

Although diphenhydramine has been in widespread use for many years without ill consequence, it is known to cross the placenta and has been detected in breast milk . This medication should therefore only be used when the potential benefit of treatment to the mother exceeds any possible hazards to the developing fetus or suckling infant .

Pharmacokinetic studies indicate no major differences in the distribution or elimination of diphenhydramine compared to younger adults . Nevertheless, diphenhydramine should be used with caution in the elderly, who are more likely to experience adverse effects . Avoid use in elderly patients with confusion .

The results of a review on the use of diphenhydramine in renal failure suggest that in moderate to severe renal failure, the dose interval should be extended by a period dependent on Glomerular filtration rate (GFR) .

After intravenous administration of 0.8 mg/kg diphenhydramine, a prolonged half-life was noted in patients with chronic liver disease which correlated with the severity of the disease . However, the mean plasma clearance and apparent volume of distribution were not significantly affected .

LD₅₀=500 mg/kg (orally in rats). Considerable overdosage can lead to myocardial infarction (heart attack), serious ventricular dysrhythmias, coma and death.

The symptoms of overdose are presented in individuals that consumed more than 99 mg/kg. Most common symptoms of overdose are abdominal pain, nausea, vomiting, lethargy, vertigo, drowsiness (somnolence), dizziness and insomnia. Other symptoms of overdose include headache, loss of consciousness, tinnitus, CNS depression, convulsions and seizures. May rarely cause metabolic acidosis, abnormal hepatic function, hyperkalemia, renal failure, dyspnea, respiratory depression, coma, acute renal failure, and apnea (primarily in very young pediatric patients).

The reported LD50 of ibuprofen is of 636 mg/kg in rat, 740 mg/kg in mouse and 495 mg/kg in guinea pig.

Precaution

Caution should be exercised with patients in whom drowsiness is undesirable e.g., drivers, machine operators. Concomitant consumption of alcohol or central nervous system (CNS) depressants will potentiate drowsiness.

Ibuprofen should be given with caution to patients with bleeding disorders, cardiovascular diseases, peptic ulceration or a history of such ulceration and in those who are receiving coumarin anticoagulants and in patients with renal or hepatic impairment.

Interaction

Diphenhydramine administration significantly reduces the absorption of the antituberculous agent para-aminosalicyclic acid (PAS) from the gastrointestinal tract. CNS depressants may potentiate the sedative action of Diphenhydramine. Anticholinergic drugs may potentiate Diphenhydramine’s anticholinergic side effects.

Increased risk of GI bleeding with warfarin, corticosteroids, SSRIs and aspirin. May reduce the natriuretic effects of diuretics. Reduced antihypertensive effect of ACE inhibitors and angiotensin II receptor antagonists. May increase toxicity of lithium and methotrexate. Increased nephrotoxicity with ciclosporin and tacrolimus.

Volume of Distribution

Diphenhydramine is widely distributed throughout the body, including the CNS . Following a 50 mg oral dose of diphenhydramine, the volume of distribution is in the range of 3.3 - 6.8 l/kg .

The apparent volume of distribution of ibuprofen is of 0.1 L/kg.

Elimination Route

Diphenhydramine is quickly absorbed after oral administration with maximum activity occurring in approximately one hour . The oral bioavailability of diphenhydramine has been documented in the range of 40% to 60%, and peak plasma concentration occurs about 2 to 3 hours after administration .

It is very well absorbed orally and the peak serum concentration can be attained in 1 to 2 hours after extravascular administration. When ibuprofen is administered immediately after a meal there is a slight reduction in the absorption rate but there is no change in the extent of the absorption.

When orally administered, the absorption of ibuprofen in adults is very rapidly done in the upper GI tract. The average Cmax, Tmax and AUC ranges around 20 mcg/ml, 2 h and 70 mcg.h/ml. These parameters can vary depending on the enantiomer form, route, and dose of administration.

Half Life

The elimination half-life ranges from 2.4-9.3 hours in healthy adults . The terminal elimination half-life is prolonged in liver cirrhosis .

The serum half-life of ibuprofen is 1.2-2 hours. In patients with a compromised liver function, the half-life can be prolonged to 3.1-3.4 hours.

Clearance

Values for plasma clearance of a 50 mg oral dose of diphenhydramine has been documented as lying in the range of 600-1300 ml/min .

The clearance rate ranges between 3-13 L/h depending on the route of administration, enantiomer type and dosage.

Elimination Route

The metabolites of diphenhydramine are conjugated with glycine and glutamine and excreted in urine . Only about 1% of a single dose is excreted unchanged in urine . The medication is ultimately eliminated by the kidneys slowly, mainly as inactive metabolites .

Ibuprofen is rapidly metabolized and eliminated in the urine thus, this via accounts for more than 90% of the administered dose. It is completely eliminated in 24 hours after the last dose and almost all the administered dose goes through metabolism, representing about 99% of the eliminated dose. The biliary excretion of unchanged drug and active phase II metabolites represents 1% of the administered dose.

In summary, ibuprofen is excreted as metabolites or their conjugates. The elimination of ibuprofen is not impaired by old age or the presence of renal impairment.

Pregnancy & Breastfeeding use

Category B: There are no adequate and well controlled studies in pregnant women using diphenhydramine hydrochloride. Therefore, diphenhydramine hydrochloride should be used in pregnancy only if clearly needed. Diphenhydramine hydrochloride has been reported to be excreted in breast milk and thus, use of diphenhydramine hydrochloride in lactating mother is not recommended.

Ibuprofen is not recommended during pregnancy or for use in nursing mothers.

Contraindication

Known hypersensitivity to Diphenhydramine Hydrochloride, Ammonium chloride is contra-indicated in presence of impaired hepatic or renal function.

Ibuprofen should not be given to patients with hypersensitivity to lbuprofen and to individuals who show nasal polyps, angioedema, bronchospastic reactivity to aspirin or other non-steroidal anti-inflammatory drug. Ibuprofen is contraindicated in patients with active or previous peptic ulceration & gastro-intestinal ulceration or bleeding.

Acute Overdose

Symptoms: Impaired consciousness; psychosis, seizures, antimuscarinic symptoms (e.g. mydriasis, tachycardia, tachyarrhythmias), resp failure, rhabdomyolysis; acute delirium with visual and auditory hallucination (topical).

Management: Supportive and symptomatic treatment. Convulsions and marked CNS stimulation may be treated with IV diazepam.

Gastric lavage, correction of blood electrolytes (if necessary). There is no specific antidote for Ibuprofen

Storage Condition

Store between 15-30° C. Protect from moisture.

Keep in a cool & dry place. Keep out of the reach of children.

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