Minoxidil topical

Over the years it has been interesting to note that many compounded products eventually become commercially available products. Recent examples might include fentanyl lozenges, minoxidil topical solution, nystatin lozenges, clindamycin topical solution, tetracaine-adrenalin-cocaine (TAG) solution, dihydroergotamine mesylate nasal spray, buprenorphine nasal spray, buffered hypertonic saline solution, and erythromycin topical solution as well as numerous other dermatological and pediatric oral liquids and some... 

Minoxidil topical. solution is u.scd to treat alopecia andro-genitica (male pattern baldness). Although (he mechanism is not clearly undcrsItKxl. topical minoxidil is believed to increa.se cutaneous bhxid How. which may stimulate hair growth. The stimulation of hair growth is attributed to va.so-dilation in the vicinity of application of the drug, re.sulting in better nourishment of (he local hair follicle.s. 

Dihydralazine and minoxidil (via its sulfate-conjugated metabolite) dilate arterioles and are used in antihypertensive therapy. They are, however, unsuitable for monotherapy because of compensatory circulatory reflexes. The mechanism of action of dihydralazine is unclear. Minoxidil probably activates K channels, leading to hyperpolarization of smooth muscle cells. Particular adverse reactions are lupus erythematosus with dihydralazine and hirsutism with minoxidil—used topically for the treatment of baldness (alopecia androg-enetica). 

Topical minoxidil is used for the treatment of male pattern baldness (alopecia androgenetica) of the vertex of the scalp. Use of the tablets, in any formulation, to promote hair growth is not an approved use. 

SR012 Sinclair, R. D., R. S. Mallari, and B. Tate. Sensitization to saw palmetto and minoxidil in separate topical extemporaneous treatments for androge-netic alopecia. Austr J Dermatol 2002 43(4) 311-312. 

Topical minoxidil is effective in reversing the progressive miniaturization of scalp hairs associated with androgenic alopecia (male pattern baldness). It is a hereditary disorder due to excessive conversion of testosterone to dehydrocorticosterone in the scalp skin in genetically susceptible men. 

Tachycardia, palpitations, angina, and edema are observed when doses of 3 blockers and diuretics are inadequate. Headache, sweating, and hypertrichosis, which is particularly bothersome in women, are relatively common. Minoxidil illustrates how one person s toxicity may become another person s therapy. Topical minoxidil (as Rogaine) is used as a stimulant to hair growth for correction of baldness. 

Topical minoxidil (Rogaine) is effective in reversing the progressive miniaturization of terminal scalp hairs associated with androgenic alopecia. Vertex balding is more responsive to therapy than frontal balding. The mechanism of action of minoxidil on hair follicles is unknown. Chronic dosing studies have demonstrated that the effect of minoxidil is not permanent, and cessation of treatment will lead to hair loss in 4-6 months. Percutaneous absorption of minoxidil in normal scalp is minimal, but possible systemic effects on blood pressure (see Chapter 11) should be monitored in patients with cardiac disease. 

N, N -Diallyl-pynmidine-2,4,6-triamine, U-7720 (23) was initially, developed as a potent antihypertensive agent. Later, its metabolite minoxidil (3) was found to be efficacious as both an antihypertensive orally and for hair growth topically. The systemic and local side effects of topical minoxidil (3) are essentially non-existent. 

In an open comparative study of androgenetic alopecia in 90 men oral finasteride (1 mg/day for 12 months n = 65) was compared with 5% topical minoxidil solution twice daily (n = 25) (22). The cure rates were 80% for oral finasteride and 52% for topical minoxidil. The adverse effects were all mild, and did not lead to withdrawal of treatment. Of the 65 men given oral finasteride, six had loss of libido, and one had an increase in body hair at other sites irritation of the scalp was seen in one of those who used minoxidil. These adverse events disappeared as soon as the treatment was withdrawn. The laboratory data did not show any statistically or clinically significant changes from baseline values to the endpoint, except for the serum total testosterone concentration, which was increased, and free testosterone and serum prostate-specific antigen in the finasteride group which were reduced from baseline values. 

Area E, Acikgoz G, Tastan HB, Kose O, Kurumlu Z. An open, randomized, comparative study of oral finasteride and 5% topical minoxidil in male androgenetic alopecia. Dermatology 2004 209 117-25. 

Diffuse non-scarring alopecia occurred in a 37-year-old premenopausal woman with relapsed breast cancer 6 months after she had started to take letrozole 2.5 mg/ day and triptorelin 3.75 mg every 28 days it resolved with topical minoxidil (20). 

Pseudoacromegaly has been reported in a patient who had taken large oral doses of minoxidil for about 10 years (722). There have been no reports of pseudoacromegaly associated with topical minoxidil. 

Until recently, the only pharmacologic preparation approved for the treatment of AGA was minoxidil, which is applied topically as a solution... 

Direct vasodilators frequently produce baroreflex-induced tachycardia, but rarely orthostatic hypotension. They are usually prescribed with a beta blocker or a centrally acting antihypertensive to minimize the reflex increase in heart rate and cardiac output. It should be noted that another member of the directly acting class of antihypertensives is minoxidil. This potent, long-acting drug has gained considerable notoriety for its use as a topical hair-restorer. Oral use can result in hirsutism (unwanted hair growth over the face as well as other parts of the body). 

SCHEME 11.33 Topically applied minoxidil requires sulfation for bioactivation. 

Liposomal systems also can form an effective drug reservoir in the upper layers of the skin. This is particularly useful for local skin therapy. Ethosomal carriers composed of phospholipid vesicular systems with alcohols are also effective at enhancing tran -dermal delivery of both lipophilic and hydrophilic compounds. The use of these ethosomes has been used in the delivery of minoxidil to the pilo-sebaceous section of the skin with better results than conventional liposomes. Similar results are reported in clinical studies with acyclovir in a topical therapy treatment of recurrent herpes labialis. Other application reports with ethosomes are patches containing testosterone (37). 

This topic has been reviewed both generally [9], and specifically for variation in the benzopyran nucleus [10]. SARs have also formed part of several comprehensive and useful reports and reviews [11-15], while full details of lead and development KCAs are regularly updated in a useful compilation [16] devoted to modulators of K channels. Hence, this section will address recent advances, and those previously reported [9, 10], where further detail is now available. These are best presented in terms of the different series of KCAs based on the prototype molecules, cromakalim (1), RP 49356 (4), pinacidil (6), and nicorandil (7) that, together with the older compounds, minoxidil sulphate (8) and diazoxide (9), now recognized as KCAs, illustrate the widening range of structural types of this classification... 

Alopecia (1) male pattern baldness (1) Topical minoxidil is worth tryin if the patient Is embarrassed by baldness. Some hair regrowth can be detected in up to S0% but it is rarely cosmetically significant. Most patients who take minoxidil orally for hypertension experience some increased hair growth. It may act by a mitogenic effect on hair follicles. The response occurs in 4-12 months stop treatment if no result in 1 year. 

Minoxidil is a vasodilator selective for arterioles rather than for veins, similar to diazoxide and hydralazine. Like the former, it acts through its sulphate metabolite as an ATP-dependent potassium channel opener. It is highly effective in severe hypertension, but causes increased cardiac output, tachycardia, fluid retention and hypertrichosis. The hair growth is generalised and although a cosmetic problem in women, it has been exploited as a topical solution for the treatment of baldness in men. 

Minoxidil (2,4-diamino-6-piperidinopyrimidine-3-oxide) is a potent vasodilator effective in severe hypertension irrespective of the cause. Isolated case reports have been published of hair growth in areas of male pattern baldness in patients treated with oral minoxidil, therefore topical minoxidil has been used for the treatment of alopecia areata and alopecia androgenica, with some success. 

Topical minoxidil stimulates new hair growth and arrests loss of hair in androgenic alopecia. Minoxidil is poorly absorbed through the skin (less than 4%) (1), and plasma concentrations of minoxidil are far less than 10% of the mean minoxidil concentration present 2 hours after oral ingestion of 5 mg, the lowest dose for the treatment of hypertension (2). Its adverse effects after topical apph-cation are therefore usually limited to the apphcation site on the scalp. They include irritant contact dermatitis, allergic contact dermatitis, and exacerbation of seborrheic dermatitis. These effects are seen in 5.7% of patients who use a 5% solution and in 1.9% of those who use a 2% formulation (3). 

A hypertensive crisis occurred in one patient after withdrawal of topical minoxidil (SEDA-16,158). 

Local adverse effects of topical minoxidil (usually in an alcohol-propylene glycol base) include dryness, irritation, pruritus, contact allergy (SEDA-11, 139), and photocontact allergy (SEDA-11,139). 

Topical minoxidil has been used to treat women with androgenic alopecia. Severe hypertrichosis of the face and the hmbs occurred in three women after 2-3 months of treatment with 5% topical minoxidil (9). The hypertrichosis disappeared from the face and arms within 1-3 months of withdrawal and from the legs after 4-5 months. 

In 11 patients allergic to topical minoxidil lotion, patch tests showed that four were positive to minoxidil itself (11). Propylene and butylene glycol are used as solvents for minoxidil in topical formulations. Nine of the 11 patients appeared to have positive patch tests to propylene glycol and one of the 11 reacted to its alternative butylene glycol. 

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