Oral contraceptives selection

Table 3. Oral Contraceptives Marketed in Selected Countries...

Since the use of combined oral contraceptives may decrease the use of selected barrier contraceptive methods that do protect against STDs (e.g., latex condoms), one of the most common risks associated with the use of oral contraceptives is the risk of acquiring an STD.8... 

As with all medications, there are potential adverse effects with combined oral contraceptives (COCs). Many side effects can be minimized or avoided by adjusting the estrogen and/or progestin content of the oral contraceptive. It is also important to have proper patient selection for oral contraceptives because some women are at increased risk for potentially serious side effects. 

A large number of oral contraceptives containing estrogens or progestins (or both) are now available for clinical use (Table 40-3). These preparations vary chemically and pharmacologically and have many properties in common as well as definite differences important for the correct selection of the optimum agent. 

A 1978 WHO report quoted an unpublished study by March in which pituitary adenomas were found in 26% of women with secondary amenorrhea following the use of oral contraceptives, yet in only 13% of cases who had not used these products (118). The difference was significant, but selection bias might have explained the results. 

There have been several reports of hepatic cholestasis in women taking both troleandomycin and oral contraceptives (361). Oxidation of troleandomycin by CYP3A4 produces a derivative (probably a nitrosylated derivative) that binds tightly to the enzyme and thereby causes inactivation. This inhibition is highly selective for CYP3A4, and hepatic accumulation of ethinylestradiol is possible. 

Q10 When choosing an oral contraceptive, a preparation with the lowest oestrogen and progestogen content that can control the cycle is selected. In older women or women with a history of venous thrombosis who require contraception, a progestogen-only preparation may be more suitable than the combined hormonal type, but unfortunately this is not a suitable choice for Shabana s problem. 

In general, more adverse systemic drug reactions are reported in women than in men, although it is not clear whether this also applies to OADRs. Among the fectors that may explain these gender differences are pharmacokinetic differences, including body size the impact of hormonal changes and the use of oral contraceptives and other medications used selectively or primarily by women. 

Oxcarbazepine, like its analogue carbamazepine, acts by blocking voltage-sensitive sodium channels. It is rapidly and extensively metabolised in the liver the of the parent drug is 2 h but that of its principal metabolite (which also has therapeutic activity) is 11 h. Unlike carbamazepine, it does not form an epoxide which may explain why oxcarbazepine has fewer unwanted effects. Oxcarbazepine is a selective inducer of a cytochrome isoenzyme that metabolises the oral contraceptive and a 50 microgram oestrogen preparation is necessary for... 

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