Drug Description

Phenergan (also called Promethazine) belongs to the group of medicines called phenothiazines. Phenergan acts by affecting the action of brain chemicals, thereby changing the course of any allergic response.
Phenergan acts almost the same way as antihistamine, as it also blocks the effects of naturally occurring histamine in the human body.
Phenergan is used for the treatment of such allergic reactions as itching, head cold, tearing, sneezing and rash. It can be also used after the operation, as it prevents vomiting, pain in the body and motion sickness. However, it can’t be used for the treatment of such respiratory diseases as pneumonia and asthma.


Consult the doctor if you’re going to give the medicine to a child under the age of 18. However, it is contraindicated to the children under the age of 2.
Inform your doctor if you have any of the following diseases: breathing difficulty, lung problems, weakened immunity, prostate diseases, stomach and cardiovascular diseases, liver dysfunction, high blood pressure, pain in the bones, etc.
The diseases of prostate can be cause by the increase in the size of gland or urinary retention, and in the case of adrenal gland it can be caused by the tumor called “pheochromocytoma”. The blood disorder caused by the low levels of calcium is known as “hypocalcemia”.
It is still unknown if the drug can affect a fetus. Therefore, you should inform your doctor about your pregnancy before starting the treatment. You should avoid taking this drug during the breastfeeding, as this drug may be released with the breast milk.


It is essential to take Phenergan strictly according to the doctor’s prescription and drug instructions. In some cases, the doctor may change the dosage to achieve better results. Avoid exceeding the dosage, as it may cause adverse effects.
Phenergan must be taken before sleep or before eating. Patients with motion sickness must take the medicine at least 1hour before starting the journey. Phenergan is usually given to the patients one day before surgery. The frequency and time of taking the medicine depends on the severity of your disease. The quantity of drug in liquid form must be measured carefully with the dosing syringe or special spoon. If you don’t have the measuring device, you should buy it at the pharmacy.
If the drug is taken by the children, the dosage depends on their weight.
Consult your doctor immediately if you don’t notice any improvements.
The dosage depends on the disease it is used for.


The average dosage is about 25 mg before sleep. However, you can also take 12.5 mg before meal and the other 12.5 mg before sleep. It is recommended to take minimum possible dosage which is enough to alleviate the symptoms.

Motion Sickness

The common dose is 25mg for the adults, divided into two dosages. The first dose must be taken 1 hour before the suggested journey.

Adverse effects

The most common adverse effects are:

  • Dry mouth
  • Vertigo
  • Vision impairment
  • Nervousness
  • Fatigue
  • Tinnitus
  • Severe adverse effects are:
  • Sleepiness and weakened body
  • Dizziness
  • Hallucinations that may cause confusion
  • Sudden cramps
  • Irregular heartbeat
  • Jaundice
  • Adverse reactions in the nervous system
  • Negative thinking and frustration

Inform the doctors about any of the above-mentioned adverse effects.

Should use choose brand or generic version of Phenergan?

Phenergan is the brand drug. There are many generic drugs like Promethazine, so you can choose between brand and generic version. Both of them have the same components, apart from several inactive elements. Usually, all generic drugs have the same impact and adverse effects as brand medications. To ensure safety, you should opt for the generic drug from the best manufacturers or choose the brand medicine.