What does the term 'first pass effect' refer to?

Choice A reason: The initial phase of drug distribution is not the correct definition of the term 'first pass effect'. Drug distribution is the process by which a drug moves from the bloodstream to the tissues and organs of the body. The initial phase of drug distribution is influenced by factors such as blood flow, tissue permeability, plasma protein binding, and tissue binding. The first pass effect is not related to drug distribution, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice B reason: The rapid absorption of a drug in the intestine is not the correct definition of the term 'first pass effect'. Drug absorption is the process by which a drug enters the bloodstream from the site of administration. The rapid absorption of a drug in the intestine depends on factors such as the drug formulation, the pH of the gastrointestinal tract, the presence of food or other drugs, and the surface area and motility of the intestine. The first pass effect is not related to drug absorption, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice C reason: The initial rapid excretion of a drug through the urinary system is not the correct definition of the term 'first pass effect'. Drug excretion is the process by which a drug or its metabolites are eliminated from the body. The initial rapid excretion of a drug through the urinary system is influenced by factors such as the renal blood flow, the glomerular filtration rate, the tubular secretion and reabsorption, and the urine pH. The first pass effect is not related to drug excretion, but to drug metabolism, which is the chemical transformation of a drug in the body.

Choice D reason: The metabolism of a drug before it reaches the systemic circulation is the correct definition of the term 'first pass effect'. Drug metabolism is the process by which a drug is chemically transformed in the body, usually by enzymes in the liver or other tissues. The first pass effect is a phenomenon of drug metabolism that occurs when a drug is administered orally and passes through the gastrointestinal tract and the liver before reaching the systemic circulation. The first pass effect can reduce the bioavailability and the effectiveness of the drug, as some or most of the drug may be metabolized and inactivated before reaching the site of action.

Choice A reason: This is correct. Constipation is a common side effect of aluminum hydroxide, as it reduces the motility of the gastrointestinal tract. The nurse should advise the client to report this symptom and to increase their fluid and fiber intake to prevent it.

Choice B reason: This is incorrect. Flatulence is not a common side effect of aluminum hydroxide. It may be caused by other factors, such as diet, swallowing air, or bacterial overgrowth in the intestines.

Choice C reason: This is incorrect. Headache is not a common side effect of aluminum hydroxide. It may be caused by other factors, such as stress, dehydration, or caffeine withdrawal.

Choice D reason: This is incorrect. Palpitations are not a common side effect of aluminum hydroxide. They may be caused by other factors, such as anxiety, heart problems, or medication interactions.