Topical Phenergan
I have received requests from local physicians to compound Phenergan cream for topical treatment of nausea. Does this product demonstrate an effective therapy for nausea and by what concentration and compounding methodology?
Promethazine (Phenergan) belongs to the class of antiemetics called phenothiazines. Phenothiazines are effective in the prevention and control of mild-to-moderate nausea and vomiting. Promethazine is available as a tablet, oral liquid, rectal suppository, and intravenous solution. Phenergan cream 2% is a product that is commercially available outside the United States. The only similar topical product available in the United States for the control of nausea and vomiting is the scopolamine patch, which is primarily used for motion sickness.
A recipe for compounding promethazine gel with a final concentration of 12.5 mg/mL is available at the Pharmacy Times Compounding Hotline Web site (see "Suggested Reading"). Topical application of medication is an effective method for drug delivery. However, the amount of medication absorbed through the skin is influenced by skin type, thickness of skin, and the area of application. Absorption can also be influenced by temperature and the addition of occlusive dressing to the area of application.
Cases of intoxication have been reported with topical administration of promethazine. With topical administration, medication is absorbed through the skin and then slowly released from the skin into the general circulation. In the case of overdosage, drug exposure can be prolonged. The benefits of topical administration of promethazine should be weighed against the variability of drug absorption through this route.
Question
I have received requests from local physicians to compound Phenergan cream for topical treatment of nausea. Does this product demonstrate an effective therapy for nausea and by what concentration and compounding methodology?
Response From the Expert
Virna Ignacio Almuete, RPh
Promethazine (Phenergan) belongs to the class of antiemetics called phenothiazines. Phenothiazines are effective in the prevention and control of mild-to-moderate nausea and vomiting. Promethazine is available as a tablet, oral liquid, rectal suppository, and intravenous solution. Phenergan cream 2% is a product that is commercially available outside the United States. The only similar topical product available in the United States for the control of nausea and vomiting is the scopolamine patch, which is primarily used for motion sickness.
A recipe for compounding promethazine gel with a final concentration of 12.5 mg/mL is available at the Pharmacy Times Compounding Hotline Web site (see "Suggested Reading"). Topical application of medication is an effective method for drug delivery. However, the amount of medication absorbed through the skin is influenced by skin type, thickness of skin, and the area of application. Absorption can also be influenced by temperature and the addition of occlusive dressing to the area of application.
Cases of intoxication have been reported with topical administration of promethazine. With topical administration, medication is absorbed through the skin and then slowly released from the skin into the general circulation. In the case of overdosage, drug exposure can be prolonged. The benefits of topical administration of promethazine should be weighed against the variability of drug absorption through this route.
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