Anagen effluvium can develop when using certain prescription drugs. The mechanisms by which the drugs promote hair loss has usually involve inhibition of cell proliferation in some way. Typically, these types of drugs are used to treat cancer.
Anagen effluvium phenotypically looks similar to telogen effluvium although it develops much more rapidly.
There are varying degrees of drug induced anagen effluvium insult. Limited drug ingestion may just slow the rate of cell division in a hair follicle making the hair fibers thin and easily breakable. Depending on the duration of drug use and the potency of the treatment some individuals may develop near universal hair loss.
Although the scalp is the primary site affected, hair loss of the eyebrows, axillary, and pubic region can also develop. Hair is very rapidly growing with a high level of cell division. In anagen effluvium the metabolic process is brought to a sudden stop making a sharp break in the production of the hair shaft. The hair fiber is then shed but, unlike telogen effluvium, the hair follicle does not enter a resting telogen state. Consequently, when conditions become more favorable, the onset of hair regrowth is equally as sudden as the initial loss. Hair follicles are not normally destroyed and will regrow hair if more favorable conditions return as after completion of chemotherapy.
Some attempts have been made to find ways to reduce the extent of hair loss when using anti cancer drugs. Some dermatologists advocate the use of a tourniquet around the scalp as drugs are injected. The restriction of blood flow to scalp skin is believed to limit the immediate effects of any drug. Other dermatologists use ice packs on the scalp to reduce blood flow and apparently reduce the drug effects on hair follicles in a similar way. However, it has been questioned whether limiting the activity of chemotherapy drugs in the scalp may also allow any cancerous cells in scalp skin to escape the drug activity.
Alternative options investigated have included using 2% minoxidil during chemotherapy with some apparent success in reducing hair loss and permitting more rapid hair regrowth after completion of the chemotherapy course (Duvic 1996). n-acetyl-cysteine used during treatment with cyclophosphamide prevents extensive hair loss (Hussein 1995) and pharmaceutical company Glaxo Wellcome are developing a gel containing a compound code named GW8510 that will help prevent chemotherapy induced hair loss. There are other experimental procedures and drugs that have been used to prevent drug induced hair loss. See the reference list below.
Common drugs causing anagen effluvium
The most common drug categories and examples of drugs causing anagen effluvium type hair loss are listed below. This is by no means an exhaustive list of drugs known to promote hair loss.
- Alkylating agents, Cyclophosphamide, Nitrogen Mustard, Chlorambucil, Thiotepa
- Antimetabolic agents, Methotrexate, 5-Fluorouracil, Fluorouracin, 6-Mercaptopurine
- Cytostatic drugs, Colchicine, Actinomycin D, Vinblastine, Vincristine, Cytosine, Doxorubicine, Arabinoside
- Antipsychotic drugs, Fluorobutyrophenone
- Antidepressant drugs, Valproic acid, Divalproex, Carbamazepine, Maprotilene, Trazodone, Haloperidol, Olanzepine, Risperidone, Clonazepam, Buspirone, Paroxetine, Fluoxetine, Sertraline
- Anticholesterinic drugs, Triparanol
- Vitamin A derivative drugs, Retinoids, Retinol, Acitretin , Isotretinoin, Etretinate, Vitamin A
- Amino acid, Mimosine
- Other drugs, Bleomycin, cytarabine, Mitomycin, Dactinomycin, Mitoxantrone, Daunorubicin, Procarbazine, Thioguanine, Etoposide, Floxuridine, Fluconazole
Also see the reference list below. Note that the side affects of most drugs are listed in drug reference books and only a few are actually published in medical journals.