Concurrent use of procaine hydrochloride and anticholinesterase agents may result in increased systemic toxicity since anticholinesterases inhibit the breakdown of procaine hydrochloride.
Concurrent use of procaine hydrochloride and antimyasthenics may result in loss of control of symptoms of myasthenia gravis due to antagonism of the effects of antimyasthenics on skeletal muscle. Temporary dosage adjustment of antimyasthenics may be required. Also antimyasthenics may have anticholinesterase activity.
CNS depressant medications
Concurrent use of procaine hydrochloride and CNS depressant medications may result in additive depressant effects.
Hyaluronidase may increase the diffusion rate of procaine hydrochloride, resulting in a decreased time of onset, but an increase in systemic toxicity.
Neuromuscular blocking agents (such as suxamethonium chloride)
Concurrent use of procaine hydrochloride and neuromuscular blocking agents may result in prolongation or enhancement of the neuromuscular blockade.
Concurrent use of procaine hydrochloride and sulfonamides may result in a reduction of the antibacterial action of the sulfonamide.
Concurrent use of acetazolamide and procaine hydrochloride may extend the plasma half-life of procaine.