Final answer:
Nausea is one of the first signs of opioid withdrawal. It is due to the cessation of opioids' anti-nausea effects. Methadone can be prescribed to help manage withdrawal symptoms.
Step-by-step explanation:
When a client's opioid therapy is being tapered off, nurses monitor for early signs of withdrawal, which can be characterized by a set of symptoms that are typically opposite to the effects of the drug. Among the options provided, nausea is one of the first signs of opioid withdrawal. This symptom emerges because opioids often act as anti-nausea and anti-diarrhea medications when in use, so their absence can lead to gastrointestinal upset. Other early signs can include sweating (diaphoresis) and agitation, but these may not appear as initial symptoms. In contrast to opioids' analgesic (pain-relieving) effects, withdrawal may also lead to increased sensitivity to pain, showcasing the body's adjustment to the lack of opioid compounds it has grown accustomed to.
In terms of treatment, medication like methadone and buprenorphine can be prescribed during the withdrawal process. These drugs help in managing withdrawal symptoms by providing a controlled reduction in opioid dependence without the high levels of euphoria associated with drugs like heroin.