When we talk about the relation between drugs and hair, we can refer to two well distinguished situations: one in which there is a will to use all the drugs to fight against hair loss and another one in which, instead, there is a will to use drugs that can cause and help hair loss.
Here below both will be illustrated and described.
Drugs against hair loss
The effectiveness of the drugs used against alopecia (hair loss) depends on the causes of it. In general, these drugs are much more effective when the alopecia is less severe and if they are precociously taken. Among the anti-hairloss drugs approved by the FDA (Food and Drug Administration) – the american institution in charge of evaluating drugs and food safety – there are pharamaceutical products such as minoxidil and finasteride.
Most used Hairloss Drugs: Minoxidil, Finasteride and Corticosteroids
Minoxidil is used to treat androgenetic and areata alopecia. The first one, also know as common baldness, is the most common one, especially in males, and is caused by the action of some hormones + a genetic predisposition. It leads to a progressive and spread hair loss, that usually does not affect the nape and the lower part of the temples (available areas for a possible hair transplant). With areata alopecia instead, we see a sudden hair loss just in little round areas; in this case there are different causes, but mainly genetic and autoimmune ones.
Minoxidil (Regaine®, Aloxidil®) is available as a 2% or 5% foam or lotion. It must be spread on the scalp twice a day; good results can be achieved after 3 or 4 months of use, but they tend to disappear when it is not taken anymore. For this reason, if after six months of regular assumption a good regrowth is not achieved, you can stop taking it.
The most common side effects include irritation of the skin, itch, dermatitis, dryness of the scalp and desquamation.
Finasteride (Propecia®) is a drug against hair loss approved for the treatment of androgenetic alopecia. It is in the form of pills that need to be taken daily. In many cases it stops hair loss and stimulates hair regrowth from the follicles that are not totally atrophied yet. Also in this case, the benefits become visible after around 12 weeks and depend on a regular use of the product.
The drug inhibits the conversion of the testosterone into diidrotestosterone, especially in the hair follicles, and therefore eliminates an important hair loss risk factor.
Also Finasteride is well tolerated by the patients. The rare side effects affect the sexual sphere, causing erectile dysfunction, low desire and a reduced ejaculate volume. The use of Finasteride is greatly not recommended to women of childbearing age, because of the big damages it can cause to the male fetus.
Corticosteroids are used against hair loss too, in particular in the cases of androgenetic or areata alopecia. In the most serious situations they are taken orally or parenterally, while for the treatment of alopecia, they are applied topically.
Their use against hair loss is justified by their anti-inflammatory and immunosuppressive properties.
Among the most used active principles, we mention betametasone (Ecoval®) and triamcinolone (Kenacort®).
When taken topically, the main side effects are irritation of the skin, sting and pain in the application site.
Other hairloss drugs
Among other drugs against hair loss, we also mention dutasteride (whose action is similar to the one of finasteride), ketoconazolo (a drug to treat fungal infections that also slows down the production of diidrotestosterone), ciclosporina and antralina (used to treat areata aloepecia), azelaico acid and estrone sulfato (used to treat female androgenetic alopecia).
Drugs that cause the loss
Different drugs can cause a temporary hair fall, amplifying a pre-existent problem or causing a permanent hair loss. Excluding medical preparations (chemotherapy) and techniques (such as radiant therapy) used in the oncological field, among the drugs that can cause or speed up hair loss we mention:
- Isotreonin and other drugs derived from vitamin A (mainly used to treat acne).
- Warfarin (Coumadin®) and eparin injections (oral or not-oral anticoagulants).
- Clofibrate and gemfibrozil (usefull to reduce cholesterol and triglycerides).
- Many antidepressants, like fluoxetin (Prozac®) and imipramin.
- Amphetamines (sometimes unconsciously used to favour weight loss).
- Some antifungals.
- Beta-blocker antihypertensives, like timolol, atenolol, metoprolol and propranolol.
- Allopurinol (used to treat gout).
- Anabolic steroids and various hormonal therapies (prednisone, testosterone and other androgens, TOS, contraceptive pills).
- Drugs for rheumatoid arthritis and FANS, like naproxene, indometacina and metotrexato.
- Drug for the treatment of thyroid dysfunctions.
- Drugs to treat parkinson’s disease, like levodopa.
- Antiulcer drugs, like cimetidina, ranitidina and famotidina.
Mechanism of action
Each of these drugs can cause, favour or speed up hair loss with a specific mechanism of action. In any case, they interrupt the natural life cycle of hair growth, causing its fall.
The type of fall (telogen effluvium or anagen effluvium) caused by the drugs depends on the active substance in them, on the dosage and on the sensibility of each person to the drug itself.
When do I have to worry?
As mentioned, not all the patients who take that drugs will lose hair, since this phenomenon depends on many different factors, including the individual sensitivity to the drug.
In general, in one day we lose a number of hair between 40 and 120; this is considered to be a fully normal phenomenon as it is part of the normal life cycle of the hair.
On the contrary, in the moment in which the hair loss becomes intese, you should worry and so turn to a doctor or ask for a specialistic visit. That’s why it is so important to inform the doctor about your health state and let him know which pharmacological cures you are undergoing.