A nurse is administering phenytoin to a client. The nurse should monitor for which of the following adverse effects?

A. Tinnitus. Phenytoin is not commonly associated with tinnitus. Ototoxicity is more frequently linked to medications such as aminoglycoside antibiotics, loop diuretics, or high-dose aspirin. While phenytoin affects the nervous system, it does not typically cause ringing in the ears. B. Bleeding gums. Gingival hyperplasia, characterized by swollen and bleeding gums, is a well-known adverse effect of phenytoin, especially with long-term use. It occurs due to an overgrowth of gum tissue and can be minimized with good oral hygiene and regular dental care. Clients should be advised to brush with a soft-bristled toothbrush and visit the dentist regularly. C. Jaundice. Although phenytoin is metabolized by the liver, hepatotoxicity and jaundice are not common side effects. However, liver function should still be monitored, particularly in clients with pre-existing liver conditions or those taking other hepatotoxic medications. D. Deep vein thrombosis. Phenytoin does not significantly increase the risk of deep vein thrombosis (DVT). While some anticonvulsants may affect coagulation factors, phenytoin is not known to cause hypercoagulability or clot formation. Clients at risk for DVT should be monitored for other contributing factors, such as immobility or genetic predisposition.