Last reviewed by Editorial Team on September 4th, 2018.
Can Morphine be take with Gabapentin?
What is Morphine?
Morphine is a drug used for the relief and management of pain which can be moderate to severe in nature. The drug is also used for the recreational purposes and is highly addictive. It is an alkaloid obtained from the seed pods of the poppy plant Papaver somniferum.
Morphine belongs to the class of drugs known as narcotic analgesics which acts by blocking the transmission of pain signals to the central nervous system (CNS) of the brain. The drug was first approved by Food and Drug Administration (FDA) in 1941.
The drug is available under generic name Morphine and marketed under various brand names including AVINza, Kadian, Morphabond, Oramorph, Roxanol, Sevredol, Filnarine, Morphgesic,MST Continus, MXL, Zomorph etc. Morphine plays a key role in the treatment of severe pain. It is also recommended for the relief of pain caused by heart attack or acute myocardial infarction.
The drug is also indicated to provide obstetrical analgesia i.e., adequate relief of labor pain. The drug is also used for the relief of severe pain in bones and joints associated with sickle cell crisis. Morphine is also prescribed during surgeries in conjunction with other agents for general, regional, or local anesthesia.
The drug also provides relief from pain occurring due to severe injuries during road accidents as well as renal colic or kidney stones. Morphine plays an important role in adjunctive therapy for the treatment of acute pulmonary edema secondary to left ventricular failure. It is also recommended during rheumatoid arthritis and osteoarthritis responsible for causing severe joint pain.
The drug is also indicated for the treatment of diarrhea and for suppressing coughing in severe cases. The drug is a benzylisoquinoline alkaloid with a molecular formula of C17H19NO3 and molecular weight of 285.33766 g/mol. The drug is chemically known as (5alpha,6alpha)-Didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol.
Morphine is available in a diverse variety of forms including capsules and tablets (both extended release and rapid release), oral solutions, injections and suppositories in varying doses. The tablets are available in strength of 15 mg, 30 mg, 60 mg, 100 mg and 200 mg, solutions as 20 mg/ml, and capsules as 30 mg, 45 mg, 60 mg, 75 mg, 90 mg, and 120 mg.
Morphine sulfate suppositories are available as 5 mg, 10 mg, 15 mg, and 30 mg suppositories whereas injectible solutions are available as 0.5, 2, 4, 5, 8, 10, 15, 25, and 50 mg/mL in 1, 2, 10, 20, 30, 50, and 250 mL ampules or vials. Moprhine is usually started at a lower dose which can be increased gradually depending upon the degree of pain only under the supervision of a doctor and it can be taken with or without food.
How does Morphine work in the body?
Morphine is a narcotic pain management drug used for the relief of pain in patients requiring opioid analgesics for more than a few days. Although, the precise mechanism of the action of Morphine is unknown but is likely to involve specific CNS opiate receptors which play crucial role in the expression of analgesic effects of Morphine.
Opiate receptors are present at discrete locations including the thalamus, hypothalamus, striatum, midbrain, limbic system, and spinal cord. There are several subtypes of opiate receptors that includes the mu-receptor, (localized in pain modulating regions of the CNS); the kappa-receptor (localized in the deep layers of the cerebral cortex); the delta-receptor (localized in the limbic regions of the CNS); and the sigma-receptor mediating the dysphoric and psychotomimetic effects.
Morphine exerts agonist activity at the mu- and kappa-receptors associated with effects such as analgesia, miosis, and/or decreased body temperature. Agonist activity at the mu-receptor also causes suppression of opiate withdrawal.
Morphine first acts on these mu-receptors present in the human brain with varying densities and the highest density being present in the posterior amygdala, thalamus, nucleus caudatus, hypothalamus, putamen, and certain cortical areas. These receptors are also found on the terminal axons of primary afferents of the spinal cord and in the spinal nucleus of the trigeminal nerve.
The drug has more affinity for the mu-receptor as compared to kappa-receptor; little, if any, activity at the sigma-receptor; and some agonist activity at the delta-receptor. Morphine causes enhanced tolerance to pain in patients and also decreases discomfort.
Morphine may also result in respiratory depression by causing a decrease in the responsiveness of the brain stem respiratory centers to increased carbon dioxide tension and to electrical stimulation. Morphine may bind to and inhibit GABA inhibitory interneurons responsible for inhibition of the descending pain inhibition pathway.
This causes pain modulation to proceed downstream even in absence of inhibitory signals. Respiratory depression is mainly mediated by mu-receptors, possibly mu2-receptors in contrast to mu1-receptors involved in analgesia; kappa- and delta-receptors may also play a role in respiratory depression. Cough-suppressant opiate receptors have also been suggested to be involved in the mechanistic action of Morphine.
Morphine and Gabapentin (Neurontin) Drug Interactions
Yes, both the drugs can be used in combination to treat the neuropathic pain. It has been found that the acute analgesic effect of Morphine gets enhanced in presence of anticonvulsant Gabapentin. Furthermore, the concomitant administration of Gabapentin and Morphine results in an increased plasma concentration of Gabapentin.
Combination of Gabapentin and Morphine is well tolerated and results in improved pain therapy, especially in pain states, including chronic and neuropathic pain, which respond poorly to opioids. Studies also indicated that the maximal tolerated doses of combination drugs i.e., Morphine and Gabapentin together were lower in comparison to the maximal tolerated doses of each drug as a single agent.
Besides, Gabapentin and Morphine when administered in combination achieved better analgesia at lower doses of each drug than either drug as a single agent. Studies in animal models also indicated that the anti-nociceptive effects of Gabapentin on Morphine might be attributed to the activation of the IL-10-HO-1 signalling pathway, which resulted in the inhibition of the expression of pro-inflammatory cytokines in neuropathic pain.
Safety and precautions while taking Morphine and Gabapentin combination
- Morphine and Gabapentin may interact with other drugs. Therefore, care should be taken when you are taking any prescription or non-prescription medicines and herbal or vitamin supplements. It is advisable that you do not start, stop or change or take any medicine unless you have discussed with your doctor or professional consult.
- Do not use the medicine if you are hypersensitive or allergic (e.g., anaphylaxis) to Morphine or Gabapentin, or any of the drug constituents.
- Do not share the medications with other persons having the similar kind of problems. Consult your doctor for more details.
- Morphine is contraindicated in case of severe asthma or breathing problems, a blockage in stomach or intestines, or a bowel obstruction known as paralytic ileus.
- Morphine should not be used in larger amounts or for longer periods as it can slow or stop your breathing. Do not crush, break, or open an extended-release pill should not be crushed, broken or opened in order to avoid exposure to a potentially fatal dose.
- Morphine may be habit-forming, even at regular doses and should not be shared with another person with a history of drug abuse or addiction.
- Morphine may cause life-threatening withdrawal symptoms in a newborn and should not be used during pregnancy. Gabapentin is also not recommended for use during pregnancy.
- Patients should avoid alcohol while using these medications. Drinking alcohol can increase certain side effects of Gabapentin and Morphine. Alcohol in combination of Morphine may cause dangerous side effects or even death.
- Gabapentin and Morphine is not recommended during breast feeding.