Pharmaceutical Benefits Scheme
Certain medications listed on the PBS are available only for specific therapeutic indications or to patients meeting specific criteria where the PBAC has deemed that the cost-benefit analysis is favourable only in those indications/patients. These are noted as "restricted benefits" on the Schedule. Medicare Australia places the onus of policing restricted benefits on the prescribers themselves and the pharmacists dispensing (unless the listing is also 'Authority Required'). For example, the COX-2 inhibitor celecoxib is listed on the PBS as a restricted benefit for the symptomatic treatment of osteoarthritis and rheumatoid arthritis. Prescribers using celecoxib for other indications are expected to indicate "non-PBS" on the prescription, and/or the pharmacist dispensing the celecoxib should charge the patient the full cost.
Vitamin A
Vitamin A, and more specifically, retinoic acid, appears to maintain normal skin health by switching on genes and differentiating keratinocytes (immature skin cells) into mature epidermal cells. Exact mechanisms behind pharmacological retinoid therapy agents in the treatment of dermatological diseases are being researched.
For the treatment of acne, the most prescribed retinoid drug is 13-cis retinoic acid (isotretinoin). It reduces the size and secretion of the sebaceous glands. Although it is known that 40 mg of isotretinoin will break down to an equivalent of 10 mg of ATRA — the mechanism of action of the drug (original brand name Accutane) remains unknown and is a matter of some controversy. Isotretinoin reduces bacterial numbers in both the ducts and skin surface. This is thought to be a result of the reduction in sebum, a nutrient source for the bacteria. Isotretinoin reduces inflammation via inhibition of chemotactic responses of monocytes and neutrophils. Isotretinoin also has been shown to initiate remodeling of the sebaceous glands; triggering changes in gene expression that selectively induce apoptosis. Isotretinoin is a teratogen with a number of potential side-effects. Consequently, its use requires medical supervision.