Final answer:
Determining the dosage of a drug involves consideration of pharmacokinetic parameters and plasma protein binding. Side effects from drugs vary widely and may depend on individual physiology and interactions with other substances.
Step-by-step explanation:
To determine the dosage of a drug, several factors must be considered including the maximum concentration (Cmax), time to reach Cmax, the plasma drug concentration-time curve (AUC), the drug's half-life (t₁), its volume of distribution at steady state (Vss), and clearance (CL). The drug's plasma protein binding must also be assessed, as it affects the circulating concentration and the pharmacological or toxicological effects.
Additionally, factors such as bioavailability, which is the proportion of the drug that enters the circulation when introduced into the body and therefore is able to have an active effect, are critical for proper dosage determination.
Common side effects of drugs include nausea, dizziness, fatigue, and more severe reactions depending on the medication and individual. Factors contributing to side effects may include individual patient physiology, other medications being taken, food interactions, and the rate at which the drug is metabolized and eliminated from the body.