Naloxone can also be administered via intramuscular or subcutaneous injection. Treatment generally involves calcium injection by intravenous, intramuscular or subcutaneous routes. Oxycodone can be administered orally, intranasally, via intravenous, intramuscular, or subcutaneous injection, or rectally. The most commonly prescribed methods are intramuscular and subcutaneous injections. If atropine is given by intramuscular or subcutaneous injection, it causes initial bradycardia. Treatment can be orally or by intramuscular or intravenous injection. ACAM2000 should not be injected by the intradermal, subcutaneous, intramuscular, or intravenous route. Palytoxin is also very toxic after intramuscular or subcutaneous injection. Codeine may instead be injected by the intramuscular or subcutaneous route. Designs exist for both intramuscular and subcutaneous injection. Ketorolac is available in intravenous and intramuscular formulations. Absorption takes the longest from this route compared to intravenous, intramuscular, and subcutaneous injections. Doses can be given by oral, intravenous or intramuscular routes. Hydroxyzine can be administered orally or via intramuscular injection. Intramuscular, subcutaneous, and transdermal options are available.