Sirdalud Use In Pregnancy & Lactation

Pregnancy: Risk Summary: As there is limited experience with the use of tizanidine (Sirdalud) in pregnant women, it should not be used during pregnancy unless the benefit clearly outweighs the risk (see PHARMACOLOGY: TOXICOLOGY: NON-CLINICAL SAFETY DATA under ACTIONS).
Animal data: Reproduction studies performed in rats and rabbits did not show evidence of teratogenicity. In rats, dose levels of 10 and 30 mg/kg/day increased gestation duration. Prenatal and postnatal pup loss was increased and development retardation occurred. At these doses, dams showed marked signs of muscle relaxation and sedation. Based on body surface area, these doses were 2.2 and 6.7 times the maximum recommended human dose of 0.72 mg/kg/day.
Lactation: Risk Summary: Small amounts of tizanidine are excreted in rat milk. Since no human data are available tizanidine (Sirdalud) should not be given to women who are breast-feeding.
Females and males of reproductive potential: Pregnancy testing: Sexually-active females of reproductive potential are recommended to have a pregnancy test prior to starting treatment with tizanidine (Sirdalud).
Contraception: Females of reproductive potential should be advised that animal studies have been performed showing tizanidine (Sirdalud) to be harmful to the developing fetus. Sexually-active females of reproductive potential are recommended to use effective contraception (methods that result in less than 1% pregnancy rates) when using tizanidine (Sirdalud) during treatment and for 1 day after stopping treatment with tizanidine (Sirdalud).
Fertility: Animal Data: No impairment of fertility was observed in male rats at a dose of 10 mg/kg/day and in female rats at a dose of 3 mg/kg/day. Fertility was reduced in male rats receiving 30 mg/kg/day and in female rats receiving 10 mg/kg/day. Based on body surface area, these doses were 6.7 and 2.2 times the maximum recommended human dose of 0.72 mg/kg. At these doses, maternal behavioral effects and clinical signs were observed including marked sedation, weight loss, and ataxia (see PHARMACOLOGY: TOXICOLOGY: NON-CLINICAL SAFETY DATA under ACTIONS).