If i take metronidazole 400mg 2 tablets a day and ofloxacin 200mg 4 tablets a day for 14 days would this reduce the effectiveness of nexplanon?

YES: In general most antibiotics will reduce the efficacy of birth control pills. So you should use condoms or abstain.

No. Not affected. : These antibiotics do not affect Nexplanon. Some drugs may cause hormonal birth control to work less well by decreasing the amount of birth control hormones in your body. Examples include griseofulvin, rifampin, St. John's wort, & drugs used to treat seizures (such as barbiturates, carbamazepine, felbamate, phenytoin, primidone, topiramate), or some HIV drugs. Take your antibiotucs as prescribed.