07-16-2004, 02:11 PM #1
Adverse affects of drugs on hair!!!!
Many drugs have significant effects on hair growth in humans. The mentioned drugs with affinity for androgen receptors, many drugs affect both androgen-dependent and androgen-independent hair. They produce either hair loss or increased growth.
• Drugs producing hair loss:
Drugs may affect hair follicles in anagen in two ways: by stopping mitosis in matrix cells (anagen effluvium) or by inducing transition of hair follicles from anagen to premature telogen (telogen effluvium). Anagen effluvium ensues a few days or weeks after drug administration, and telogen effluvium only after two to four months. In both cases hair loss is reversible. Anagen effluvium can be produced by cytotoxic drugs (alkylating agents, alkaloids) and telogen by: heparin, vitamin A and its derivatives, interferons, angiotensin converting enzyme blockers, beta-blockers (propranolol, metoprolol), the antiepileptic trimethadione, levodopa, nicotinic acid, salts of gold, lithium, cimetidine, amphetamine, isoniazid and antiinflammatory drugs (ibuprofen, acetylsalicylic acid). Precise molecular mechanisms of action for the majority of these drugs remains unknown.
• Drugs producing increase in hair growth:
Drugs may increase growth of androgen-dependent hairs (hirsutism) or of all hair (hypertrichosis). Hirsutism can be caused by testosterone , danazol, ACTH, metyrapone, anabolic steroids , glucocorticoids and some antiepileptics - phenytoin and carbamazepine. Hypertrichosis can be produced by cyclosporine, minoxidil and diazoxide. Minoxidil and diazoxide open potassium channels in cell membranes leading to hyperpolarisation. The opening of potassium channels could be main mechanism of their hypertrihotic action. Furthermore, it has been shown that other drugs which open potassium channels (P-1075, cromakalim) are able to produce hypertrihosis.
Endogenous substances that affect hair growth
SUBSTANCE SITE OF ACTION EFFECT ON HAIR GROWTH
Basic fibroblast growth factor (bFGF) Dermal papilla cells increase (H)
Platelet-derived growth factor (PDGF) Dermal papilla cells increase (H)
Transforming growth factor beta (TGF- )
Dermal papilla cells decrease (H)
Hair matrix cells decrease (H)
Fibroblast growth factor type 5 (FGF5) Hair matrix cells decrease (H)
Epidermal growth factor (EGF) Hair matrix cells decrease (H)
Keratinocyte growth factor (KGF) Hair matrix cells increase (R)
Insulin -like growth factor I (IGF-I) Hair matrix cells increase (H)
Substance P Unknown increase (M)
Parathyroid hormone (PTH) Unknown decrease (M)
1,25 - dihydroxyvitamin D3 (1,25/OH/D3) Unknown concentration
low = increase (H)
high = decrease (H)
Table 1. Endogenous substances which affect hair growth. The species studied is noted in parentheses adjacent to the effect: H = human, R = rat, and M = mouse. It should be noted that there are vast differences between animal models and human hair follicles.
The hair follicle has a treasure of control mechanisms which influence its growth. Many are under the influence of androgens, while the others are highly autonomous. Thanks to the very long chain of factors controlling hair growth we have the opportunity to intervene in a number of ways.
Hirsutism, as well as hair loss, are serious psycho-social problems for affected persons. With the recent advances in the study of hair growth, design of both selective and safe drugs for solving these major problems should be only a matter of time.
Last edited by Elizabeth; 07-16-2004 at 05:28 PM.
07-22-2004, 05:29 AM #2LM1332 Guest
U know whats funny i started to lose hair randomly in the frontal area. No drugs no cycle no anything. And i did this, everytime i took a shower i massaged the area where hair was disapearing and like magic hair grew back...What a phenomenon! Great read btw
09-14-2004, 11:03 AM #3Junior Member
- Join Date
- Aug 2003
- Stamford, CT
So according to this ritalin, caffeine and ephedirne causes hair thinning and/or loss?
09-16-2004, 10:21 AM #4Originally Posted by dknyspe
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