Diphenhydramine And Naproxen

Diphenhydramine And Naproxen Uses, Dosage, Side Effects, Food Interaction and all others data.

Diphenhydramine is an antihistamine with anticholinergic and sedative effects. It competes with histamine for H1-receptor sites on effector cells in the GI tract, blood vessels and respiratory tract.

Diphenhydramine has anti-histaminic (H1-receptor), anti-emetic, anti-vertigo and sedative and hypnotic properties . The anti-histamine action occurs by blocking the spasmogenic and congestive effects of histamine by competing with histamine for H1 receptor sites on effector cells, preventing but not reversing responses mediated by histamine alone . Such receptor sites may be found in the gut, uterus, large blood vessels, bronchial muscles, and elsewhere . Anti-emetic action is by inhibition at the medullary chemoreceptor trigger zone . Anti-vertigo action is by a central antimuscarinic effect on the vestibular apparatus and the integrative vomiting center and medullary chemoreceptor trigger zone of the midbrain .

Naproxen, a propionic acid derivative, is a prototypical NSAID. It reversibly inhibits the cyclooxygenase-1 and -2 (COX-1 and -2) enzymes, thus resulting in reduced synthesis of prostaglandin precursors. It can inhibit platelet aggregation, has anti-inflammatory, analgesic and antipyretic actions.

Naproxen is an established non-selective NSAID and is useful as an analgesic, anti-inflammatory and antipyretic. Similar to other NSAIDs, the pharmacological activity of naproxen can be attributed to the inhibition of cyclo-oxygenase, which in turn reduces prostaglandin synthesis in various tissues and fluids including the synovial fluid, gastric mucosa, and the blood.

Although naproxen is an effective analgesic, it can have unintended deleterious effects in the patient. For instance, naproxen can adversely affect blood pressure control. A study found that use of naproxen induced an increase in blood pressure, although the increase was not as significant as that found with ibuprofen use.

Further, studies have found that the risk of upper gastrointestinal bleeding is on average four-fold higher for individuals taking NSAIDs. Other factors that increase the risk of upper gastrointestinal bleeding include concurrent use of corticosteroids or anticoagulants, and a history of gastrointestinal ulcers.

Diphenhydramine And Naproxen
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	Diphenhydramine And Naproxen
Generic	Diphenhydramine + naproxen
Weight	25mg + 220mg
Type	Oral tablet
Therapeutic Class
Manufacturer
Available Country	United States
Last Updated:	September 19, 2023 at 7:00 am

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

Naproxen is used for the relief of symptoms of rheumatoid arthritis, both of acute flares and long term management of the disease. It is also used in the diseases of rheumatoid osteoarthritis (degenerative arthritis), ankylosing spondylitis, juvenile rheumatoid arthritis, tendinitis, brusitis, acute gout, acute musculoskeletal disorders (such as sprains, direct trauma and fibrositis), migraine and dysmenorrhoea.

Diphenhydramine And Naproxen 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, ExpectorantAcute Gouty Arthritis, Acute Migraine, Ankylosing Spondylitis (AS), Arthritis, Backache, Bursitis, Extra-Articular Rheumatism, Fever, Flu caused by Influenza, Headache, Juvenile Idiopathic Arthritis (JIA), Menstrual Distress (Dysmenorrhea), Migraine, Muscle Spasms, Nasal Congestion, Osteoarthritis (OA), Pain, Post-traumatic pain, Postoperative pain, Primary Dysmenorrhoea, Rheumatoid Arthritis, Rheumatoid Arthritis, Juvenile, Seasonal Allergic Rhinitis, Sinusitis, Tendinitis, Toothache

How Diphenhydramine And Naproxen 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 .

As with other non-selective NSAIDs, naproxen exerts it's clinical effects by blocking COX-1 and COX-2 enzymes leading to decreased prostaglandin synthesis. Although both enzymes contribute to prostaglandin production, they have unique functional differences. The COX-1 enzymes is constitutively active and can be found in normal tissues such as the stomach lining, while the COX-2 enzyme is inducible and produces prostaglandins that mediate pain, fever and inflammation. The COX-2 enzyme mediates the desired antipyretic, analgesic and anti-inflammatory properties offered by Naproxen, while undesired adverse effects such as gastrointestinal upset and renal toxicities are linked to the COX-1 enzyme.

Dosage

Diphenhydramine And Naproxen 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

Tablet & Suppository (Adult)-

Rheumatic disorders:The usual initial dose of naproxen is 250 mg twice daily adjusted to 500 mg to 1000 mg daily in 2 divided doses.
Juvenile arthritis: A dose of 10 mg/kg body weight daily in 2 divided doses is used for children over 5 years of age.
Acute gout: An initial dose of 750 mg followed by 250 mg every 8 hours.
Dysmenorrhoea: 500 mg may be given initially followed by 250 mg in every 6-8 hours.

Syrup (Children over 5 years)-

In juvenile arthritis: The usual dosage of Naproxen is 10 mg/kg/day taken in two doses at 12-hour intervals is recommended.

Gel:Naproxen gel is to be applied 2-6 times a day as required and is not recommended for use in children.

Side Effects

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

Gastro-intestinal discomfort: nausea, diarrhoea and occasionally bleeding and ulceration.

Hypersensitivity reactions: notably with bronchospasm, rashes and angioedema.

CNS side effect: drowsiness, headache, fluid retention, vertigo, hearing disturbances such as tinnitus, photosensitivity.

A few instances of jaundice, impairment of renal function, thrombocytopenia, and agranulocytosis have been reported.

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.

Although the over-the-counter (OTC) availability of naproxen provides convenience to patients, it also increases the likelihood of overdose. Thankfully, the extent of overdose is typically mild with adverse effects normally limited to drowsiness, lethargy, epigastric pain, nausea and vomiting. Although there is no antidote for naproxen overdose, symptoms will typically subside with appropriate supportive care.

Naproxen is classified as Category B during the first 2 trimesters of pregnancy, and as Category D during the third trimester. Naproxen is contraindicated in the 3rd trimester since it increases the risk of premature closure of the fetal ductus arteriosus and should be avoided in pregnant women starting at 30 weeks gestation.

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.

Naproxen should be used with caution in patients with cardiac, hepatic and renal impairment, coagulation defect, and previous history of gastro-intestinal ulceration. The drug is contraindicated in patients with a history of hypersensitivity to aspirin or any other NSAID - which includes those in whom attacks of asthma, angioedema, urticaria or rhinitis have been precipitated by aspirin or any other NSAID.

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.

Antacid: The absorption of naproxen can be altered by antacids.

Aspirin: Plasma concentration of Naproxen can be reduced when aspirin is given concomitantly, this appeared to be due to increased exeretion of naproxen.

Diuretics: Naproxen diminish the effect of frusemide.

Probenecid: It increase the plasma concentration of Naproxen.

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 .

Naproxen has a volume of distribution of 0.16 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 .

Naproxen is available as a free acid and sodium salt. At comparable doses, (naproxen 500 mg = naproxen sodium 550 mg) they differ slightly in their rates of absorption, but otherwise they are therapeutically and pharmacologically equivalent. Naproxen sodium achieves a peak plasma concentration after 1 hour, while peak plasma concentration is observed after 2 hours with naproxen (free acid). There are no differences between the 2 forms in the post-absorption phase pharmacokinetics. The difference in initial absorption should be considered when treating acute pain, since naproxen sodium may offer a quicker onset of action.

The mean Cmax for the various formulations (immediate release, enteric coated, controlled release etc.) of naproxen are comparable and range from 94 mcg/mL to 97.4 mcg/mL. In one pharmacokinetic study, the mean Tmax of naproxen 500 mg (immediate release) given every 12 hours over 5 days was 3 hours, compared to a mean Tmax of 5 hours for Naprelan 1000 mg (controlled release) given every 24 hours over 5 days. In this same study, the AUC_0-24hr was 1446mcgxhr/mL for naproxen immediate release and 1448 mcgxhr/mL for the controlled release formulation. A separate study comparing the pharmacokinetics of Naprosyn tablets and EC-Naprosyn observed the following values: Tmax and AUC_0-12hrs of EC-Naprosyn were 4 hours and 845 mcgxhr/mL respectively, and Tmax and AUC_0-12hrs values of Naprosyn were 1.9 hours and 767 mcgxhr/mL respectively.

When given in combination with sumatriptan the Cmax of naproxen is roughly 36% lower compared to naproxen sodium 550 mg tablets, and the median Tmax is 5 hours.

Based on the AUC and Cmax of naproxen, Vimovo (naproxen/esomeprazole combination product) and enteric-coated naproxen may be considered bioequivalent.

Overall, naproxen is rapidly and completely absorbed when administered orally and rectally. Food may contribute to a delay in the absorption of orally administered naproxen, but will not affect the extent of absorption.

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 elimination half-life of naproxen is reported to be 12-17 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 .

Naproxen is cleared at a rate of 0.13 mL/min/kg.

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 .

After oral administration, about 95% of naproxen and it's metabolites can be recovered in the urine with 66-92% recovered as conjugated metabolite and less than 1% recovered as naproxen or desmethylnaproxen. Less than 5% of naproxen is excreted in the feces.

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.

There are no well controlled studies in pregnant women. The drug should not be used during pregnancy unless clearly needed. Because of the possible adverse effects of prostaglandin inhibiting drugs on neonates, use in nursing mothers must be avoided.

Contraindication

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

Naproxen suppository in contraindicated in children under 12 years of age. The suppository is contraindicated also in patients with any inflammatory lesions of rectum or anus and in patients with recent history of rectal or anal 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.

Significant overdosage of the drug may be characterized by drowsiness, heartburn, indigestion, and nausea or vomiting. It is not known what dose of the drug would be life threatening.