A patient’s age can affect a patient’s pharmacodynamic and pharmacokinetic processes. L.M. is 80 years old and is therefore considered to be geriatric. The elderly have decreased hepatic function, renal function, and acidity, which alter pharmacokinetic processes (Thürmann, 2020). Metoprolol, omeprazole, digoxin, warfarin, and paracetamol undergo hepatic metabolism. A decrease in liver function caused a decrease in the hepatic metabolism of these oral drugs taken by L.M., leading to increased circulation concentration. High concentration in circulation causes increased susceptibility to experiencing side effects and toxicity of the drugs. The renal system is vital in urination and the excretion of drugs from the body. Metoprolol, warfarin, digoxin, paracetamol, and omeprazole are mainly excreted through the renal system. L.M. is elderly and therefore has a decreased renal function leading to a higher concentration of these drugs in circulation hence severe side effects and toxicity. The elderly have increased acidity, leading to increased metabolism of drugs such as omeprazole that require an acidic P.H. to metabolize.
Changes in the pharmacokinetic and pharmacodynamic processes impact a patient’s recommended therapy. Therapy is adjusted by dose adjustments, dose increase or decrease, withdrawal of drugs, change in the duration of therapy, or alteration of dosing. L.M. is experiencing an altered level of consciousness and delirium despite being compliant with her drug therapy plan; therefore, her drug therapy plan needs improvement. L.M. takes digoxin 0.25mg Q.D. and has a laboratory result of dig 2.4 and a normal potassium level of 4.0. Toxic levels of digoxin are more than 2.4 ng/mL; therefore, L.M.’s digoxin level is almost on the toxic level. Digoxin toxicity presents neurological symptoms such as altered consciousness and delirium (Cummings & Swoboda, 2022). The decreased renal and hepatic function causes increased digoxin levels in the system; hence L.M. is experiencing toxic side effects. There is a need to decrease the dose or frequency of digoxin. L.M. has an INR of 3.8, yet the target value for INR in atrial fibrillation is 2.0 to 3.0 using warfarin (Patel et al., 2022). An INR of 3.8 suggests the patient is unresponsive to warfarin; therefore, there is a need to increase the dose or frequency of warfarin. The patient has a blood pressure of 101/58 mmHg, which is within the normal range showing that the dosage and frequency of metoprolol are effective. L.M. has a BUN of 33, which is above the normal value, showing kidney failure. Paracetamol causes nephrotoxicity; therefore, further damage to the kidneys, since L.M. has chronic kidney disease, should be prevented by lowering the dosage or frequency of paracetamol (Agrawal & Khazaeni, 2022).
Digoxin is prescribed for the management of atrial fibrillation. I would decrease the frequency from 0.5 mg Q.D. to 0.5mg B.D. in addition, warfarin 3mg Q.D. will be altered to warfarin 4mg Q.D. for two days, followed by an INR check and further dose adjustment according to the results. Metoprolol is maintained at 25mg Q.D. However, the patient is encouraged to monitor her blood pressure daily at home to prevent and report any readings showing hypotension and hypertension. Omeprazole is prescribed for the management of hypertension. Elderly patients whose drug therapy plans include several medications tend to get confused. Therefore, I will withdraw omeprazole and educate the patient on non-phar