Pharmacy Clinic

Isotretinoin

•        Is a synthetic 13-cis-isomer of tretinoin, usually more effective than tretinoin and
available as 10-, 20- or 40-mg oral capsules
•        It is the only systemic agent that decreases sebum production and reverses the
abnormal epithelial desquamation process; it also can decrease the population of P. acnes in
the sebaceous follicle, making it the treatment of choice for patients with severe nodulocystic
acne
•        The initial dose of isotretinoin is 0.5 to 1.0 mg/kg or 40 mg to 80 mg per day, with a
usual course of therapy of four to five months
•        Transient exacerbation of acne may occur during the first few weeks of therapy, but
most patients respond well over time
•        Usually no further therapy is needed. Satisfactory response rate has been as high as
90 percent with a low relapse rate of 31 percent at nine years
•        Retreatment with three to five courses has been found safe and effective
•        Adverse effects of systemic isotretinoin include cheilitis (lip inflammation), dry skin,
pruritus, photosensitivity and mild to moderate musculoskeletal symptoms
•        Topical lubricants can alleviate some of these symptoms
•        Dryness of the eye also can occur, so patients wearing contacts should be warned not
to wear them. Pseudo-tumor cerebri (benign intracranial hypertension) can occur if isotretinoin
is taken concurrently with tetracycline;
•        More serious side effects include decreased night vision, hypertriglyceridemia,
abnormal liver function tests, electrolyte imbalance and elevated platelet count

•        These side effects usually are reversible once therapy is discontinued.Chronic use of
systemic retinoids up to 15 years has failed to reveal long-term adverse effectsisotretinoin is
contraindicated throughout pregnancy due to teratogenic effectsMajor human fetal
abnormalities include hydrocephalus, microcephaly, external ear abnormalities, facial
dysmorphia and thymus gland abnormalitiescontraception should be used throughout therapy
and continued for at least one month after the last doseDue to these serious adverse effects
and overuse potential, strict guidelines exist for isotretinoin therapyThe product's label has
recently been revised due to isolated reports of depression, psychosis and rare suicidal
thoughts and actions. Pharmacists should be particularly alert for such reactions and consider
discontinuing isotretinoin should they appearPatients should have follow-up for suicide risk
evaluationAcne is often associated with depression, and distinguishing situational depression
from drug-induced depression may be difficultClearly, as acne improves, so should the
patient's mood and self-image.

•        Before initiating treatment with isotretinoin, the patient should have a complete blood
count, serum transaminase measurement and lipid profile to serve as baseline determinants
and to exclude unsuitable candidates
•        Additionally, serum triglyceride and transaminase levels should be measured on a
monthly basis to monitor potential side effects
Acne treatment