"Metformin is used when diet and exercise program to control high blood sugar in people with type 2 diabetes blood sugar levels. Metformin reduces the amount of sugar in the blood."
Clomiphene can lead to multiple ovulations, and hence increasing the chance of twins. Clomid sends a message to the pituitary gland to release the hormones that stimulate the growth of egg containing ovarian follicles.
"Metronidazole should be used with caution in patients with active or chronic severe peripheral and central nervous system diseases due to the risk of neurological aggravation. If other medication is taken while taking Flagyl. Metronidazole is one of the rare examples of a drug developed against a parasite which has since gained broad use as an antibacterial agent."