Mirena contains 52 mg of levonorgestrel (LNG). Initially, LNG is released at a dose rate of approximately 20 mcg/day. This rate decreases progressively to half that value after 5 years. Mirena must be removed by the end of the fifth year and can be replaced at the time of removal with a new Mirena if continued contraceptive protection is desired. Drug interactions and warnings include potential interactions with insulin , warfarin (Coumadin) and steroids. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Mirena should not be used during pregnancy. This device can cause severe infection, miscarriage , premature birth , or death of the mother if it is left in place during pregnancy. Tell your doctor right away if you become pregnant while using the Mirena intrauterine system. Small amounts of progestins such as those in Mirena pass into breast milk. If you have recently had a baby and are breastfeeding, wait until your baby is at least 6 weeks old before you start using Mirena.
In clinical trials of HIV-1 uninfected individuals, decreases in BMD were observed. In the iPrEx trial, a substudy of 503 subjects found mean changes from baseline in BMD ranging from –% to –% across total hip, spine, femoral neck, and trochanter in the TRUVADA group compared with the placebo group, which returned toward baseline after discontinuation of treatment. Thirteen percent of subjects receiving TRUVADA versus 6% of subjects receiving placebo lost at least 5% of BMD at the spine during treatment. Bone fractures were reported in % of the TRUVADA group compared with % in the placebo group. No correlation between BMD and fractures was noted [see Clinical Studies ]. The Partners PrEP trial found similar fracture rates between treatment and placebo groups (% and %, respectively); no BMD evaluations were performed during this trial [see Clinical Studies ].
One concept to reduce the adverse effects of opioids is the use of very small doses of opioid antagonists. 25 – 28 The rationale is that agents such as naloxone (Narcan) have a biphasic effect whereby very low doses reduce the incidence of opioid adverse effects and may augment the analgesic effect. 25 , 28 Much of the data are limited to the inpatient setting with intravenous administration of the opioid antagonist. 25 – 27 Concomitant administration of intravenous naloxone with morphine infusions has been studied, but the results have been mixed. 25 – 27 More research is needed before this treatment is implemented as part of routine practice.