Drug Interactions between epinephrine and IFE-Bimix 30/1

MONITOR: Concomitant use of multiple vasodilator drugs for the treatment of erectile dysfunction (ED) may increase the risk of additive adverse effects, including hypotension, dizziness, syncope, prolonged erection, or priapism. However, available data are conflicting. For example, approximately 4.9% and 7.1% of people in selected studies using single ingredient intracavernosal injections (ICIs) of papaverine reported experiencing painful/prolonged erections and priapism, respectively. Conversely, selected studies of people using ICIs containing papaverine and phentolamine reported an increase in the average rate of prolonged/painful erections to approximately 8.9%, but a reduction in the average rate of priapism to approximately 5.5%. Additionally, 1 case series reported an increase in dizziness and syncope when patients used both oral agents and ICIs to treat ED. Clinical data are not available for all possible combinations. The route of administration and amount of medication absorbed systemically may affect the clinical significance and severity of this interaction.

MANAGEMENT: Most clinical guidelines advise caution and closer clinical monitoring for patients on erectile dysfunction (ED) regimens that include multiple vasodilative agents due to the potential for additive adverse effects. Some drug manufacturers recommend avoiding combinations due to the potential risks and a lack of established data on safety. However, some of these medications are available as combinations (either commercially or via compounding) and some ED guidelines indicate that combination therapy may be appropriate in certain situations. Healthcare providers should refer to the product labeling and appropriate treatment guidelines for the most up to date information and recommendations; as well as, counsel patients on potential adverse effects and what to do should they occur.

MONITOR: Theoretically, the pharmacologic effects of agents that act through agonism at the alpha receptor may be antagonized by those that act via antagonism at the same receptor, and vice versa. Alpha-1 agonists and alpha agonists with beta-agonist effects exert opposing effects on vascular tone and blood pressure than alpha-1 antagonists. Some of these agents act on both alpha-1 and alpha-2 receptors, though they may have a stronger affinity for one or the other. The severity of the interaction may also be influenced by the degree of systemic absorption of each agent.

MANAGEMENT: Monitoring for diminished effects on blood pressure and vasoconstriction is recommended if an alpha-agonist (e.g., epinephrine, norepinephrine, ephedrine, metaraminol) is coadministered with an alpha-antagonist (e.g., phentolamine, phenoxybenzamine, terazosin). If the concomitant alpha agonist being used also acts on beta receptors, the effects of unopposed beta stimulation should also be considered.