A client is ordered .9mg ondansetron, IV, PRN q6 hours for nausea. The nurse anticipates which of the following sources to cause potential medication error?

A) Hypersensitivity reaction: A hypersensitivity reaction typically involves an immune response where the body reacts to a substance as if it were harmful, leading to symptoms like rashes, swelling, or difficulty breathing. However, low hemoglobin and low white blood cell counts are not typical signs of a hypersensitivity reaction. This would involve more common allergic symptoms like itching or swelling, rather than hematologic changes.

B) Paradoxical reaction: A paradoxical reaction refers to when a medication causes an effect opposite to the expected result. For example, a sedative causing agitation instead of sleepiness. While a paradoxical reaction can involve unexpected effects, the hematologic changes (low hemoglobin and white blood cell counts) in this scenario do not align with this type of response.

C) Idiosyncratic reaction: An idiosyncratic reaction is an unusual or unexpected response to

a medication that is not related to the drug's pharmacologic properties or the dose given. It may be related to genetic factors or other individual differences in how a person metabolizes or responds to the drug. The low hemoglobin and low white blood cell counts in this case are unusual effects of diphenhydramine and suggest an idiosyncratic response, where the client’s body is reacting in an unexpected way to the medication.

D) Anti-cholinergic reaction: Anti-cholinergic reactions are typically related to symptoms caused by the blocking of acetylcholine, such as dry mouth, blurred vision, urinary retention, or constipation. While diphenhydramine has anti-cholinergic properties, the symptoms described (low hemoglobin and white blood cell counts) are not typical of an anti-cholinergic reaction.

A) The stomach acid has a lower pH level which results in increased absorption: While it is true that neonates have a lower gastric pH, which could affect the absorption of certain medications, this factor does not directly increase the risk for drug toxicity. Lower pH may increase absorption for some drugs, but it is not as critical in neonates as the immaturity of other organs, such as the liver and kidneys, which are responsible for drug metabolism and excretion.

B) The glomerular filtration rate (GFR) is increased causing rapid excretion: In neonates, the glomerular filtration rate (GFR) is actually decreased, not increased. This leads to slower excretion of medications, which can increase the risk for drug toxicity, especially for drugs that rely on renal elimination. This decreased renal function can result in accumulation of the drug in the bloodstream, potentially leading to toxicity.

C) The liver enzyme system responsible for drug metabolism is not fully developed: The liver enzyme system in neonates is immature, which significantly impacts the metabolism of drugs. Enzymatic activity is critical for breaking down medications to their active or inactive forms. Due to the underdeveloped liver function, drugs may not be metabolized properly, leading to a longer half-life and an increased risk for drug toxicity. This is a key factor in the increased risk of toxicity in neonatal clients.

D) The albumin levels are elevated due to rapid growth and protein binding is enhanced: Neonates typically have lower albumin levels, not elevated levels. Albumin is crucial for binding medications, and lower levels in neonates can result in more free (unbound) drug circulating in the bloodstream, which can increase the risk of drug toxicity. Elevated albumin would theoretically reduce this risk, but this is not typically the case in neonates.