How is morphine administered?

Morphine is a Western medicine; clinically, morphine sulfate or morphine hydrochloride is used. Common dosage forms include tablets, sustained-release tablets, controlled-release tablets, solutions, suppositories, and injectables. It is a potent analgesic indicated for severe acute pain unresponsive to other analgesics—such as pain resulting from major trauma, battlefield injuries, burns, or advanced cancer. So, how is morphine administered? The following section addresses this question.

How Is Morphine Used?

Morphine and its derivatives are the primary agents used clinically to relieve severe pain and represent the most widely utilized potent analgesics worldwide. Although morphine carries a risk of addiction, it possesses significant therapeutic value. The specific administration of morphine must be individualized according to the patient’s clinical condition. Its use is substantially limited by the development of tolerance and physical dependence. Currently, no highly effective treatment exists for clinical opioid detoxification; while some existing detoxification medications demonstrate good efficacy, they themselves carry potential for dependence.

For example, in acute myocardial infarction or acute left heart failure, patients often experience severe pain and agitation. Morphine is primarily used here for sedation and analgesia. The typical dose is 3–5 mg administered subcutaneously or via intravenous bolus injection—both routes are acceptable and considered safe. However, the dose should not exceed 5 mg. When using morphine for pain control, dosing intervals must account for its pharmacokinetic profile; generally, half an ampoule is administered via intravenous bolus, with appropriate time intervals between doses.

Knowledge Expansion: Side Effects of Morphine

1. Constipation

Constipation is the most common adverse effect associated with morphine and other opioid analgesics. It occurs early during therapy and persists throughout treatment, with patients rarely developing tolerance over time. Additionally, morphine stimulates the chemoreceptor trigger zone in the medulla oblongata, predisposing patients to nausea and vomiting.

2. Respiratory Depression

Morphine reduces the sensitivity of the medullary respiratory center to carbon dioxide and suppresses the pontine respiratory adjustment center, leading to decreased respiratory rate and central respiratory depression. If respiratory depression occurs shortly after morphine administration, temporal association supports morphine as the causative agent.

3. Dizziness and Somnolence

Dizziness and somnolence commonly occur during the first few days of therapy and typically resolve spontaneously within several days. In rare cases, excessive sedation may progressively worsen. Elderly patients or those with impaired hepatic or renal function exhibit slower morphine metabolism and elimination, resulting in elevated plasma concentrations and enhanced central nervous system depression—potentially manifesting as neuropsychiatric symptoms.

The above provides an overview of morphine administration. We hope this information is helpful to you.