Indications & Uses
Histerzin is indicated for:
Dosage Reference
Reference Information Only
Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.
Adults:
Oral dose for adults: Start with one 25 mg tablet at night. This may be increased to two or three 25 mg tablets at night if necessary. In allergic conditions, more frequent administration, twice or three times daily, may be necessary, starting with one or two 10 mg tablets and increasing as required. Elderly: No specific dosage recommendations. Children: They may be treated more conveniently with the elixir containing 5 mg per 5 ml. As an antihistamine in allergy, children aged 2 to 5 years may be given 5 to 15 mg, and children aged 5 to 10 years 10 to 25 mg. Where two doses are required in 24 hours, the lower dose stated should be given. As a sedative, children aged 2 to 5 years may be given 15 to 20 mg, and children aged 5 to 10 years 20 to 25 mg, given as a single night-time dose. Parenteral dose for adults: 25 to 50 mg by deep intramuscular injection or, in an emergency, by slow intravenous injection after diluting the 2.5% solution to 10 times its volume with water for injection. The maximum parenteral dose is 100 mg. Children aged 5 to 10 years: 6.25 to 12.5 mg by deep intramuscular injection.
Side Effects
Nervous system disorders: Frequency Unknown: Neuroleptic Malignant Syndrome the elderly are particularly susceptible to the anticholinergic efects and confusion due to Histaphen, somnolence, dizziness, headaches, extrapyramidal efects including muscle spasm, tic-like movements of the head and face. A very serious and sometimes deadly health problem called neuroleptic malignant syndrome (NMS) may happen. Stop treatment and call your doctor right away if you have high fever, muscle cramps or stifness, dizziness, very bad headache, fast heartbeat, confusion, agitation, hallucinations, or are sweating a lot. Immune System Disorders- Frequency unknown: Allergic reactions, including urticaria, rash, pruritus, and anaphylaxis, have been reported. Skin and Subcutaneous Tissue Disorders- Frequency unknown: Photosensitivity reaction Metabolism and Nutrition Disorders- Frequency unknown: Anorexia Gastrointestinal Disorders- Frequency unknown: Epigastric discomfort, dry mouth Eye Disorders- Frequency unknown: Blurred vision Blood and Lymphatic System Disorders- Frequency unknown: Blood dyscrasias including hemolytic anemia, agranulocytosis Renal and Urinary Disorders- Frequency unknown: Urinary retention Psychiatric Disorders- Frequency unknown: Infants, newborns and premature are susceptible to the anticholinergic efects of promethazine, while other children may display paradoxical hyperexcitability, restlessness, nightmares, disorientation Cardiac Disorders- Frequency unknown: Palpitations, arrhythmias Vascular disorders- Frequency unknown: Hypotension Hepatobiliary disorders- Frequency unknown: Jaundice General Disorders and Administration Site Conditions- Frequency unknown: Tiredness Use Histaphen only as recommended. Do not exceed the recommended dose. There have been case reports of promethazine abuse. Do not take for longer than 10 days.
Cautions & Contraindications
Warnings & Precautions
Promethazine should not be used in children and adolescents who show signs and symptoms suggestive of Reye's syndrome. Histaphen may thicken or dry lung secretions and make it harder to cough them up, so it should be used with caution in patients with asthma, bronchitis or bronchiectasis. Care is also needed in patients with severe coronary artery disease, narrow angle glaucoma, epilepsy, hepatic insufficiency or renal insufficiency. Caution should likewise be exercised in patients with bladder neck obstruction or pyloro-duodenal obstruction.
Contraindications
Promethazine must not be used in children under two years of age, and it must not be given to neonates or premature infants. It is also contraindicated in anyone with hypersensitivity to promethazine or to any of the excipients. Phenergan should not be used in patients who are in a coma or who have CNS depression of any cause. Phenergan should be avoided in patients who have taken monoamine oxidase inhibitors within the previous 14 days.