Which of the following isn't a side effect of pain killers?

Pain killers, also known as analgesics, can produce a variety of side effects as they impact the central nervous system and other physiological systems. Common side effects include nausea, dizziness, and blurred vision.

Nausea is frequently experienced as the digestive system is affected by alterations in the central nervous system, which can lead to a feeling of queasiness. Dizziness can occur as a side effect due to the depression of the central nervous system, which may affect balance and coordination. Blurred vision is another possible outcome, as pain management drugs may influence the visual processing pathways or muscle control around the eyes.

Coughing and sneezing, however, are generally not recognized as side effects of pain killers. These reactions are more closely associated with respiratory irritants or conditions affecting the respiratory tract rather than being direct effects of analgesic medications. Thus, the absence of coughing and sneezing in the context of potential pain killer side effects is why this option is correctly identified as not being a typical side effect.