Introduction
Phenergan VC, a combination of promethazine hydrochloride and phenylephrine hydrochloride, is an oral solution used to treat upper respiratory symptoms such as cough, runny nose, and sneezing. Here, we will delve into the clinical trials, market analysis, and projections for this medication.
Clinical Trials and Safety Profile
Clinical Studies
There have been no adequate and well-controlled studies of promethazine in pregnant women, and animal reproduction studies have not been conducted with the combination of promethazine and phenylephrine[1][5].
Safety Profile
The safety profile of Phenergan VC includes several notable side effects:
- Promethazine: Common side effects include sedation, sleepiness, blurred vision, dry mouth, and dizziness. Rare but serious side effects can include extrapyramidal symptoms, confusion, and disorientation[1].
- Phenylephrine: Side effects can include restlessness, anxiety, nervousness, dizziness, and hypertension[1].
Overdose Information
Overdose symptoms can range from mild central nervous system depression to profound hypotension, respiratory depression, and unconsciousness. Paradoxical reactions, particularly in children, can include hyperexcitability and nightmares[1].
Market Analysis
Current Market Status
Phenergan VC, along with its variant containing codeine (Promethazine VC with Codeine), has been discontinued under the brand name in the U.S. However, generic versions may still be available and approved by the FDA[4][5].
Market Demand
The demand for upper respiratory combination medications remains steady due to the common occurrence of cold and flu symptoms. However, the market is highly competitive, with numerous other products available.
Competitive Landscape
The market for cough and cold medications is dominated by well-established brands and generic alternatives. Phenergan VC competes with other combination products that offer similar symptom relief, such as those containing antihistamines, decongestants, and sometimes codeine for cough suppression.
Projections
Future Market Trends
Given the discontinuation of the brand name and the availability of generic alternatives, the market share of Phenergan VC is expected to stabilize rather than grow significantly. However, the overall demand for upper respiratory medications is likely to remain consistent due to seasonal fluctuations and the ongoing need for symptom relief.
Regulatory Considerations
Future projections must consider regulatory changes and safety updates. For instance, the FDA's scrutiny of codeine-containing products due to concerns about opioid abuse may impact the prescribing habits for Promethazine VC with Codeine, potentially affecting the market for Phenergan VC as well[4].
Patient Preferences and Healthcare Trends
Patients are increasingly seeking medications with fewer side effects and lower risks of dependency. This trend may influence prescribing practices, with healthcare providers opting for alternative treatments that offer similar efficacy with a better safety profile.
Dosage and Administration
Recommended Dosage
The recommended dosage for Phenergan VC is as follows:
- Adults and children 12 years and over: 1 teaspoonful (5 mL) every 4 to 6 hours, not to exceed 6 teaspoonsful (30 mL) in 24 hours.
- Children 6 to under 12 years of age: ½ to 1 teaspoonful (2.5 to 5 mL) every 4 to 6 hours, not to exceed 6 teaspoonsful (30 mL) in 24 hours.
- Children 2 to under 6 years of age: ¼ to ½ teaspoonful (1.25 to 2.5 mL) every 4 to 6 hours. It is not recommended for children under 2 years of age[1].
Drug Interactions and Precautions
Drug Interactions
Promethazine can affect various laboratory tests, including pregnancy tests and glucose tolerance tests. It should be used cautiously in patients with cardiovascular disease or impaired liver function[1].
Precautions
Phenylephrine should be used with caution in patients with cardiovascular disease, particularly hypertension. The combination should be avoided in pregnant women unless clearly needed due to the lack of adequate studies[1].
Patient Counseling and Monitoring
Monitoring
Patients should be closely monitored for respiratory depression, especially within the first 24-72 hours of initiating therapy. Reevaluation is necessary for patients with unresponsive cough to rule out underlying pathology[4].
Patient Counseling
Patients should be advised to avoid engaging in hazardous tasks requiring mental alertness, such as driving or operating machinery, due to the sedative effects of promethazine. They should also be informed about the risks of dependency and the importance of adhering to the prescribed dosage[4].
Key Takeaways
- Clinical Trials: Limited controlled studies, particularly in pregnant women.
- Market Analysis: Steady demand but competitive market; brand name discontinued.
- Projections: Stable market share with potential impact from regulatory changes.
- Dosage and Administration: Specific dosages for different age groups; not recommended for children under 2 years.
- Drug Interactions and Precautions: Caution needed with cardiovascular and liver conditions; affects laboratory tests.
- Patient Counseling and Monitoring: Close monitoring for respiratory depression and adherence to dosage.
FAQs
What is Phenergan VC used for?
Phenergan VC is used to treat upper respiratory symptoms such as cough, runny nose, and sneezing.
What are the common side effects of Phenergan VC?
Common side effects include sedation, sleepiness, blurred vision, dry mouth, and dizziness.
Can Phenergan VC be used in children?
Yes, but with specific dosage guidelines. It is not recommended for children under 2 years of age.
Is Phenergan VC available under its brand name?
No, the brand name has been discontinued in the U.S., but generic versions may be available.
What precautions should be taken when using Phenergan VC?
Patients with cardiovascular disease or impaired liver function should use it cautiously. It should also be avoided in pregnant women unless clearly needed.
How should patients be monitored while taking Phenergan VC?
Patients should be closely monitored for respiratory depression, especially within the first 24-72 hours of initiating therapy.
Sources
- RxList: Phenergan Vc (Promethazine HCl and Phenylephrine HCl Syrup)
- PLOS ONE: Exploratory study on “lean” or “sizzurp” using national survey data
- DrugBank Online: Phenytoin: Uses, Interactions, Mechanism of Action
- Drugs.com: Promethazine VC with Codeine: Package Insert / Prescribing Info
- Drugs.com: Promethazine VC: Package Insert / Prescribing Information
