Accutane, Isotretinoin
ACCUTANE
Accutane [isotretinoin], marketed by Roche Laboratories, is used in the treatment of acne. Isotretinoin is an isomer of tretinoin. Accutane basically decreases the amount of sebum secreted by the sebaceous glands and helps prevent/cure acne.
Acne vulgaris:
What exactly is acne?
Our skin especially, over the face has a structure called as the pilo-sebaceous unit [skin structures consisting of a hair follicle and its associated sebaceous gland]. It contains the hair follicle and the sebum gland along with its duct. Now, the function of sebum gland is to secrete sebum which then gets expressed on the skin surface. It has got some antibacterial property.
Sebum is oily in consistency and if there is increased expression of sebum then it might block the opening of the pilo-sebaceous duct. Due to this there is no drainage from the duct and this leads to the development of comedones. They are initially white, also called as white comedones and later they form black comedones. These comedones eventually lead to the formation of pimples.
The most common site is the face though you do get them on the neck, back and chest.
Usually associated with dandruff/seborrhic dermatitis but then dandruff is not a causative factor, at least that’s what the doctors have to say till date.
People with oily skin are more prone to get acne.
Other causes are:
- family history
- Hormonal activity like menstruation or puberty which is associated with increased levels of hormones.
- Stress
- Improper diet
- Hyperactivity of sebum gland
- Bacteria [Propionibacterium acnes (P. acnes) is the anaerobic bacterium that causes acne]
- Use of anabolic steroids
Why is acne so dreaded?
Well the worst part about the acne is that they often leave behind a scar which is very much detested. These scars are more commonly known as blemishes.
Adolescent age group is socially very vulnerable and so this [Acne] can be a cause of depression amongst them with a few documented proofs of suicide.
However acne is usually self limiting disease and shouldn’t be troublesome after one crosses 25 years of age.
It has been documented that newly diagnosed acne patients have low levels of vitamin A in their blood.
There is an also decreased level of vitamin E
Mechanism of action
Though the exact mode of action of Accutane [isotretinoin] is not known, recent studies suggest that Accutane [isotretinoin] decreases the sebum production from the sebaceous glands
Also, tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells causing extrusion of the comedones.
INDICATIONS:
- Nodulo-cystic and conglobate acne
- Severe acne
- Acne which has not responded to adequate course of systemic antibacterial
- Acne associated with psychological problems
Severe Recalcitrant Nodular Acne
Accutane [isotretinoin] is indicated for the treatment of severe recalcitrant nodular acne. In this type of acne, the nodules are inflammatory lesions with a diameter of 5 mm or greater. The nodules may become suppurative or hemorrhagic. “Severe,” by definition, means “many” as opposed to “few or several” nodules. Because of significant adverse effects associated with its use, Accutane [isotretinoin] should be reserved for patients with severe nodular acne who are unresponsive to conventional therapy, including systemic antibiotics. In addition, Accutane is indicated only for those female patients who are not pregnant, because Accutane can cause severe birth defects
A single course of therapy for 15 to 20 weeks has been shown to result in complete and prolonged remission of disease in many patients. If a second course of therapy is needed, it should not be initiated until at least 8 weeks after completion of the first course, because experience has shown that patients may continue to improve while off Accutane. The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth
DOSAGE:
Adults: initially 500 mcg/kg daily in 1-2 divided doses with food for 4 weeks. If the response is good then continue for further 8-12 weeks. If the response is little then increase the dose to 1mg/kg daily for 8-12 weeks. If intolerant, then reduce the dose to 100-200 mcg/kg daily. Usually given for 16 weeks, repeat course is normally not required.
Children: not recommended
CONTRAINDICATIONS:
- Renal impairment
- Hepatic impairment
- Hypervitaminosis A
- Hyperlipidemias
SPECIAL PRECAUTIONS
- Exclude pregnancy
- Avoid blood donation during treatment and at least one month after treatment
- History of depression
- Monitor lipid function tests
- Diabetes
- Dry eye syndrome
- Avoid keratolytics
SIDE EFFECTS
- Nausea
- Headache
- Malaise
- Drowsiness
- Sweating
- Benign intracranial hypertension
- Myalgia
- Arthralgia
- Dry skin
- Dry lips, nasal mucosa, pharyngeal mucosa, conjunctiva
- Visual disturbances
Samir is the author of
Accutane, Isotretinoin
information located at
Genericsmed.com
site
References:
- Drug Today, July-September 2005 Edition, page 618
- Pharmacology and Pharmacotherapeutics, R.S.Satoskar, S.D.Bhandarkar, S.S.Ainapure, Revised 17th Edition, pg 846-847
- http://www.rocheusa.com/products/accutane/pi.pdf
- http://www.rxlist.com/cgi/generic/isotret_ad.htm
- http://www.drugs.com/accutane.html
- http://en.wikipedia.org/wiki/Accutane
