| Recommended Dose and Dosage Regimen | The recommended dose of morphine varies depending on the severity of pain, the patient’s opioid tolerance, and individual response to treatment. For moderate to severe acute pain in opioid-naive patients, the typical starting dose of morphine sulfate immediate-release tablets is 5-15 mg orally every 4 hours as needed for pain. For chronic pain management, the initial dose may range from 10-30 mg orally every 4 hours. Extended-release formulations of morphine sulfate (e.g., MS Contin) may be administered at a starting dose of 15-30 mg orally every 12 hours, with subsequent adjustments based on pain intensity and tolerance. Dosage adjustments are necessary in patients with hepatic or renal impairment, elderly patients, and those at increased risk of respiratory depression. Individualize the dose based on the patient’s pain severity, response to treatment, and risk of adverse effects. Follow your healthcare provider’s instructions regarding dosing and administration. |
| Frequency of Administration | The frequency of morphine administration depends on the formulation and indication. Immediate-release morphine may be given every 4 to 6 hours as needed for pain relief. Extended-release formulations are typically administered every 8 to 12 hours for sustained analgesia. |
| Route of Administration | Morphine is administered orally, intravenously, intramuscularly, subcutaneously, or via epidural or intrathecal routes, depending on the formulation and clinical situation. |
| Mechanism of Action (MOA) | Morphine is a potent opioid analgesic that acts primarily as an agonist at mu-opioid receptors in the central nervous system. By binding to mu-opioid receptors, morphine inhibits the transmission of pain signals, alters pain perception, and produces analgesia. Additionally, morphine can activate kappa and delta opioid receptors, leading to a range of pharmacological effects, including analgesia, sedation, respiratory depression, euphoria, and physical dependence. |
| Pharmacokinetics (PK) | Morphine undergoes extensive hepatic metabolism to active metabolites, primarily morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), which contribute to its analgesic effects. The onset of action of immediate-release morphine is typically within 15-30 minutes when administered orally or intravenously, with peak plasma concentrations reached within 30-90 minutes. The elimination half-life of morphine ranges from 2 to 4 hours, but may be prolonged in patients with hepatic or renal impairment. Metabolites are excreted mainly in the urine. |
| Pharmacodynamics (PD) | Morphine exerts its pharmacodynamic effects primarily through agonist activity at mu-opioid receptors in the central nervous system. Activation of mu-opioid receptors inhibits neurotransmitter release, particularly substance P, resulting in decreased transmission of pain signals and analgesia. Morphine also modulates the activity of other neurotransmitter systems involved in pain processing, including gamma-aminobutyric acid (GABA), dopamine, and norepinephrine, leading to additional analgesic, sedative, and euphoric effects. Other pharmacodynamic effects of morphine include respiratory depression, cough suppression, miosis, and gastrointestinal effects such as constipation. |
| Pathophysiology | Morphine is indicated for the management of moderate to severe acute and chronic pain that requires opioid analgesia. Pain conditions that may be treated with morphine include postoperative pain, cancer pain, traumatic injuries, and severe chronic pain syndromes. Morphine is also used for palliative care in patients with terminal illness to alleviate suffering and improve quality of life. |
| Primary Indications | Moderate to severe acute pain, chronic pain, cancer pain, palliative care. |
| Contraindications | Contraindications to morphine use include hypersensitivity to morphine or other opioids, severe respiratory depression, acute or severe bronchial asthma, paralytic ileus, and significant respiratory depression in the absence of resuscitative equipment. Use caution in patients with impaired pulmonary function, head injuries, increased intracranial pressure, hypotension, and renal or hepatic impairment. |
| Purpose of Taking Medication | The purpose of morphine therapy is to provide effective analgesia and alleviate moderate to severe pain in patients with acute or chronic pain conditions. Morphine is used to improve quality of life and functional status in patients experiencing pain that is not adequately controlled by non-opioid analgesics or other interventions. It may be used as part of a multimodal analgesic regimen for comprehensive pain management. |
| Usage Instructions | Take morphine orally with or without food, as directed by your healthcare provider. If using liquid formulation, measure the dose carefully with a proper measuring device. For extended-release formulations, swallow the tablets whole; do not crush, chew, or dissolve. Follow your healthcare provider’s instructions regarding dosing schedule, titration, and adjustments. |
| Precautions and Care | Patients taking morphine should be closely monitored for signs of respiratory depression, sedation, hypotension, and gastrointestinal effects such as constipation and ileus. Use caution when driving or operating machinery, as morphine may cause drowsiness, dizziness, or impairment of cognitive and motor skills. Avoid alcohol and other central nervous system depressants while taking morphine, as they may potentiate respiratory depression and sedation. |
| Dietary Considerations | There are no specific dietary considerations associated with morphine use. Maintain a balanced diet and adequate hydration to support overall health and well-being during opioid therapy. |
| Missed Dose | If a dose of morphine is missed, take it as soon as remembered, unless it is almost time for the next scheduled dose. Do not double the dose to make up for a missed one. Resume the regular dosing schedule and consult your healthcare provider if unsure about missed doses or medication instructions. |
| Possible Side Effects | Common side effects of morphine may include drowsiness, dizziness, sedation, nausea, vomiting, constipation, dry mouth, and sweating. Serious adverse effects may include respiratory depression, hypotension, bradycardia, urinary retention, and opioid dependence or withdrawal symptoms with prolonged use. Contact your healthcare provider if you experience severe or persistent side effects. |
| Storage and Disposal | Store morphine tablets and liquid formulations at room temperature away from light and moisture. Keep the medication out of reach of children and pets. Unused or expired medication should be disposed of properly according to local regulations or guidelines for controlled substances. |
| Overdose or Emergency | In case of morphine overdose or emergency, seek immediate medical attention or contact a poison control center. Overdose may lead to severe respiratory depression, coma, and death. Naloxone, an opioid antagonist, may be administered as an antidote to reverse opioid effects and restore respiratory function in cases of opioid overdose. |
| Monitoring and Laboratory Tests | Patients receiving morphine therapy require regular monitoring of vital signs, including respiratory rate, blood pressure, and heart rate, especially during initiation of therapy and dose adjustments. Laboratory tests such as renal and hepatic function tests may be performed to assess treatment response and detect potential adverse effects. Pain intensity and functional status should be assessed regularly to evaluate the effectiveness of morphine therapy. |
