How does this medication work? What will it do for me?
Coal tar shampoo belongs to the family of medications known as antipsoriatics and antiseborrheics. It is used to treat itchy, oily skin conditions of the head and scalp such as psoriasis, seborrheic dermatitis, and dandruff. Coal tar appears to have some anti-inflammatory properties, reducing itch and helps to remove scales that are associated with psoriasis. It may also slow down the growth of skin cells.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are using this medication, speak to your doctor. Do not stop using this medication without consulting your doctor or pharmacist.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to use this medication if their doctor has not recommended it.
What form(s) does this medication come in?
Tersa Tar is no longer being manufactured for sale in Canada. For brands that may still be available, search under coal tar shampoo. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options.
How should I use this medication?
Coal tar shampoo should be used twice a week for the first 2 weeks, then 1 or 2 times a week thereafter. To use the shampoo, wet your hair and scalp with lukewarm water. Apply the shampoo to your scalp, massage, and rinse. Repeat, working up a rich lather. Allow shampoo to remain on your scalp for a few minutes, then rinse well with lukewarm water.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a different application schedule from the ones listed here, do not change the way that you are using the medication without consulting your doctor.
This medication should not be used around the genital, groin, or rectal areas.
Avoid contact with your eyes. If eye contact occurs, flush well with water and contact your doctor.
Coal tar may stain clothing. It can also cause a yellowish tint to occur in blond or grey hair.
It is important to use this medication exactly as suggested by your doctor or pharmacist. If you miss using the shampoo on a scheduled day, use it the next day and continue with your regular schedule. Do not apply a double dose to make up for a missed one. If you are not sure what to do after missing an application, contact your doctor or pharmacist for advice.
Store this medication in an airtight container. Keep it away from cold and out of reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not use this medication if you:
- are allergic to coal tar or any ingredients of the medication
- have an inflamed scalp
- have open or infected sores on the scalp
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is used in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who uses this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people using this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- mild stinging
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- skin irritation not present before using this medication
- skin rash with or without pimples containing pus
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Eye contact: Avoid contact with eyes. If eye contact occurs, flush well with water and call your doctor.
Staining: This medication may stain clothing, bedding, and grey or dyed hair.
Sunlight: Treated areas may be more sensitive to sunlight. Wear a hat when going outside to protect the treated areas from sunlight.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if coal tar shampoo passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
What other drugs could interact with this medication?
There may be an interaction between coal tar shampoo and any of the following:
- medications that make the skin more sensitive to sunlight (e.g., hydrochlorothiazide, ciprofloxacin, moxifloxacin, tetracycline, amiodarone)
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.