Levonorgestrel. consider

Thromboembolic disorders Patients who develop active thrombophlebitis or thromboembolic disease should have the levonorgestrel capsules removed. Also consider removal in women who will be immobilized for a prolonged period due to surgery or other illnesses. 

The two principal implants that release levonorgestrel, i.e. the six-capsule Norplant and the two-rod Jadelle are considered by authoritative reviewers to have essentially equal rates of drug release, pregnancy, and adverse events over 5 years of use (1). 

Levonorgestrel EHC is not suitable as a regular means of contraception, and women who repeatedly ask for supplies should be advised to consider longterm methods. 

An intrauterine device (progestasest) that releases low amounts of progesterone locally is available for insertion on a yearly basis. Its effectiveness is considered to be 97-98% contraceptive action probably is due to local effects on the endometrium. Another intrauterine device (MIRENA) releases levonorgestrel for up to 5 years. It again is thought to act primarily by local effects. 

A study in a group of 10 women found that the sedative effects of a single 1.3-microgram/kg dose of intravenous clonidine were increased by a combined oral contraceptive (ethinylestradiol/levonorgestrel 30 micrograms/150 or 250 micrograms). The clinical importance of this is uncertain. Consider also Antihypertensives + Hormonal contraceptives ,... 

Candesartan cilexetil 8 mg daily had no effect on the pharmacokinetics of ethinylestradiol and levonorgestrel in a combined oral contraceptive, and no ovulation occurred during concurrent treatment. No special precautions would therefore appear to be needed. Consider also Drospirenone + Potassium-sparing drugs , p.977, for a possible interaction between angiotensin II receptor antagonists and drospirenone, and Antihypertensives + Hormonal contraceptives , p.880. 

In a placebo-controlled, crossover study, 18 women taking an oral contraceptive (ethinylestradiol/levonorgestrei 30/150 micrograms) for at least 3 months were also given ziprasidone 20 mg twice daily for 8 days. The only change in the pharmacokinetics of the two steroids was an approximately 30-minute increase in the time to maximum plasma concentration of the levonorgestrel, but this was not considered to be clinically significant. No adverse effects occurred. It was concluded that combined use is safe and that ziprasidone does not affect the efficacy of this oral contraceptive and is also unlikely to affect the metabolism and therefore effieaey of other similar contraceptives. 

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