Ketoconazole Shampoos Explained
Ketoconazole (sometimes seen under the brand names Xolegal and Nizoral) is an over-the-counter and prescription medication used to treat seborrheic dermatitis, dandruff, hair loss and fungal infections of the skin. It can also be used to treat the symptoms of Cushing's syndrome and hirsutism (excessive hair growth).
Belonging to the azole antifungals class of pharmaceutical medications, ketoconazole stops fungal growth by inhibiting the activity of certain enzymes associated with the development of fungal cell walls. Due to its anti-androgenic properties, ketoconazole is also used as a prescription topical to treat hair loss attributed to androgenic alopecia.
Approved by the U.S. FDA in 1981 as an antifungal medication, ketoconazole has since then become one of the most commonly prescribed drugs for skin infections. In 2013, the FDA enacted rigorous limitations on the use of oral ketoconazole due to validated reports of ketoconazole tablets causing serious liver and adrenal gland injuries. Currently, Nizoral oral tablets should only be prescribed for persistent fungal infections that have not responded to other treatments. However, topical Nizoral (shampoos, creams, gels and foams) is not associated with adrenal or liver damage nor has it been found to be contraindicated for other medications.
The FDA has updated the labeling of Nizoral tablets to include the following warnings:
- Ketoconazole (Nizoral) tablets should not be prescribed for dermatophyte or Candida infections. Physicians are permitted to prescribe ketoconazole tablets for histoplasmosis, blastomycosis and other serious fungal infections when standard therapies fail to improve the infection
- Fungal infections of nails or skin cannot be treated with Nizoral tablets due to harmful side effects
Ketoconazole for Hair loss: What Does The Science Say?
Today, consumer can purchase shampoo containing two percent ketoconazole as an over-the-counter product. A prescription is needed to obtain ketoconazole shampoo containing more than two percent ketoconazole. In cases involving individuals with androgenic alopecia, doctors sometimes treat this type of genetic hair loss with a combination of five percent ketoconazole and a 5 alpha-reductase inhibitor such as finasteride.
Finasteride and other 5 alpha-reductase inhibitors are medications that block enzymes from converting testosterone into dihydrotestosterone (DHT). By increasing testosterone levels and decreasing DHT levels in the body, 5 alpha-reductase inhibitors enhance the ability of ketoconazole to stimulate the activity of anagen hair follicles and thicken the width of new hairs.
So does ketoconazole for hair loss work? One early study investigating the efficacy of ketoconazole for hair loss found that the effect of using 2% ketoconazole shampoo daily indicated a positive, "significant action" of ketoconazole on treating androgenic alopecia.
Published in a 2014 edition of the Journal of Dermatology, the study found that applying two percent ketoconazole daily for three weeks to clipped areas of mice dorsal skin had a "significant stimulatory effect" on hair follicles and hair growth compared to the clipped group that did not have ketoconazole applied. Researchers repeated the experiment, noted the same results, and concluded that ketoconazole is effective as a hair growth stimulant for people with androgenic alopecia and seborrheic dermatitis with hair regression.
Other studies have further investigated the role that ketoconazole plays in disrupting the DHT pathway and hair loss. A male sex hormone implicated in male and female pattern baldness, DHT (in excess) can cause shrinkage of hair follicles and shorter hair growth cycles. A combination of genetics and high levels of DHT may expedite thinning of hair and eventual hair loss. However, some DHT is necessary to help regulate the four hair growth phases: anagen (growing); catagen (transition); telogen (resting); and exogen (shedding). Too much DHT will substantially shorten the anagen phase, which negatively impacts the other three phases.
Reasons why men and women have higher than normal levels of DHT include: • Too many DHT receptors in hair follicles (genetic) • An increased sensitivity to androgen (male and female hormones) receptors • Localized production of DHT is abnormally high • Excessive production of testosterone causes increase in DHT
Before prescribing ketoconazole for hair loss, doctors will evaluate the pattern and general nature of baldness, examine any family history of baldness, and sometimes order laboratory tests to assess blood androgen levels.
Nizoral for Hair Loss in Women
To investigate the efficacy of two percent topical ketoconazole vs two percent topical minoxidil in women with female pattern hair loss, researchers treated 20 women with ketoconazole and 20 women with minoxidil.
Results of this study indicated: • Women treated with two percent minoxidil experienced visible results at four months • Women treated with two percent ketoconazole experienced visible results at six months • Little to no side effects (minor skin redness, irritation, itchiness) were reported by both groups • Subjects' satisfaction with ketoconazole and minoxidil did not differ between groups
Researchers concluded that further studies are needed to determine if three, four or five percent ketoconazole can be used to accelerate hair growth in women with female pattern baldness without causing side effects.
In older women, hair loss is commonly attributed to menopause, estrogen loss and the interplay of androgenic alopecia genes with menopause. Many reproductive-aged women who experience hair thinning and/or hair loss suffer from polycystic ovarian syndrome (POCS), a metabolic disorder involving abnormally high levels of testosterone and aldosterone. Characterized by hypertension, insulin resistance and obesity, POCS may cause younger women to lose their hair due to excess testosterone shrinking hair follicles and suppressing estrogen's benefits for hair growth and overall health. Women diagnosed with POCS may discuss the possibility of treating their hair loss with prescription ketoconazole in conjunction with standard POCS treatment.
Ketoconazole or Nizoral for Hair Loss: Are They Safe?
Available as a shampoo or cream, prescription ketoconazole should be used daily for treatment of fungal infections and/or hair loss. Nizoral shampoo can be purchased at most pharmacies and large department stores for treatment of dandruff and associated itching, scaling and flaking of the scalp. Nizoral contains only one percent ketoconazole and is not recommended for treating androgenic alopecia or other types of hair loss.
Nizoral shampoo and prescription ketoconazole may cause adverse effects that diminish over time. The most commonly reported side effects include:
• Blisters on the scalp that may be sore to the touch • Dry, itchy skin • Changes to hair texture • Oilier than normal hair and/or scales • Moderate to severe stinging and itching to areas where medicine was applied
People using Nizoral or prescription ketoconazole should contact their doctor as soon as possible if side effects continue to worsen or do not go away within a few days of starting treatment.
Over-the-counter Nizoral for hair loss can be used daily as an anti-dandruff shampoo too. Prescription ketoconazole should only be used as directed by a clinician for treating fungal infections or hair loss due to androgenic alopecia.
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