Pentazine

Promethazine is a prescription medication used to treat allergic reactions and nausea. Promethazine belongs to a group of drugs called antihistamines. It blocks the effect of histamine, a chemical in the body that causes symptoms of allergic reactions. Promethazine also belongs to another group of drugs called antiemetics, which reduce feelings of nausea.

Promethazine comes as a tablet, oral solution (liquid), rectal suppository, and a liquid to be injected into a muscle.  It is usually taken once daily at bedtime or before meals every six to twelve hours as needed to relieve symptoms of allergy or nausea. 

Tell your doctor if you are breastfeeding or plan to breastfeed.  It is not known if promethazine is excreted in human breast milk or if it will harm your nursing baby.

Promethazine should not be used in pediatric patients less than 2 years of age because of the potential for fatal respiratory depression. Postmarketing cases of respiratory depression, including fatalities, have been reported with use of promethazine in pediatric patients less than 2 years of age. Caution should be exercised when administering Promethazine to pediatric patients 2 years of age and older.

Promethazine Injection can cause severe chemical irritation and damage to tissues regardless of the route of administration. Irritation and damage can result from perivascular extravasation, unintentional intra-arterial injection, and intraneuronal or perineuronal infiltration. Adverse reactions include burning, pain, thrombophlebitis, tissue necrosis, and gangrene. In some cases, surgical intervention, including fasciotomy, skin graft, and/or amputation have been required.

Due to the risks of intravenous injection, the preferred route of administration of Promethazine Injection is deep intramuscular injection. Subcutaneous injection is contraindicated