Drugs that are used in relation to allergen-specific immunotherapy (SIT) can be separated into pharmacoprophylaxis to avoid or decrease local and systemic adverse effects of SIT and in co-medications to treat other diseases. Regarding pharmacoprophylaxis, H1-antihistamines are able to reduce local and mild systemic, but not severe systemic side effects of SIT. H1-antihistamines do not attenuate the efficacy of SIT. Severe systemic side effects have been blocked in some cases with omalizumab; currently this agent can be used off-label during venom SIT. With regard to co-medication, the concomitant use of immunomodulating drugs during SIT must be individualized, if the effective profile and side effects of the immunomodulating drug are well-known and a negative effect on SIT is not likely. Recently approved immunosuppressive drugs and biologics are perceived critically due to their unpredictable immunologic effects. For forensic reasons cardioselective beta blockers should be discontinued although no data are available demonstrating adverse effects. If discontinuation is not justified and venom SIT is indicated, SIT can be performed while taking beta blockers. In contrast, ACE-inhibitors should always be stopped in patients with insect venom allergy.