Paracetamol and Diphenhydramine

Cold Preparations · Antihistamine/Para-aminophenol derivative

Indications

Relief of bedtime pain particularly headache, migraine, backache, rheumatic and muscle pain, toothache, period pain.

Dosage

Adults and Children =12 yrs: 2 tablets with water, 20 mins before bedtime. Do not take more than 2 tabs in 24 hrs. Do not take more than 10 consecutive nights. Children <12 yrs: Not recommended.

Adverse Effects

Nausea, vomiting, stomach upset, dizziness, drowsiness, tiredness, difficulty in passing urine, chest tightness, thickening of phlegm, allergic reactions (skin rash, itching, shortness of breath, swelling of the mouth or face), breathing problems, seizures, difficulty of muscle coordination, heart rhythm, unexplained bruising or bleeding, sudden weight loss, loss of appetite, yellowing of the eyes and skin, dry mouth, sedation, unsteadiness, blurred vision, difficulty concentrating, feeling restless or excitable, confusion, tingling sensation in the skin, muscle twitching.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Porphyria. Precautions: Hepatic or renal impairment. History of epilepsy, seizure disorders. Narrow-angle glaucoma. Obstruction in stomach or gut. Difficulty passing urine. Myasthenia gravis. Enlarged prostate. COPD, asthma, bronchitis.

Interactions

MAOIs, tricyclic antidepressants, atropine, beta-blockers, metoclopramide, domperidone, metoprolol, venlafaxine, colestyramine, dicycloverine, hyoscine, anticoagulants e.g. warfarin.

Advice to Patient

Swallow whole tab with water. Do not drive or operate machinery during treatment. Avoid alcohol.

Pharmacokinetics

PARACETAMOL: Onset of action: Oral: <1 hr. IV: Analgesia: 5-10 min. Antipyretic: Within 30 min. Peak effect: IV: Analgesic: 1 hr. Duration: IV, Oral: Analgesia: 4-6 hrs. IV: Antipyretic: =6 hrs. Absorption: Primarily absorbed in small intestine, minimal absorption from stomach (varies by dosage form). Metabolism: Hepatic. Half-life elimination: Neonates: 7 hrs. Infants: Approx. 4 hrs. Children: 3 hrs. Adolescents: Approx. 3 hrs. Adults: Approx. 2 hrs. CrCl<30 mL/min: 2-5.3 hrs. Time to peak, serum: Immediate release: 10-60 min. IV: 15 min. Excretion: Urine. DIPHENHYDRAMINE: Duration: Histamine-induced wheal suppression: =10 hours. Histamine-induced flare suppression: =12 hours. Metabolism: Extensively hepatic; smaller degrees in pulmonary and renal systems; significant first-pass effect. Bioavailability: 42% to 62%. Half-life elimination: Children: 5 hours (range: 4 to 7 hours).…

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.