Why opiates cause nausea

Osmotics and Hyperosmotics: An osmotic agent may be attempted if a patient does not have a sufficient response to stimulant laxatives.

Bulk-forming laxatives are generally not recommended because they require ample fluid intake, which may not be appropriate for some patient populations. Bulk-forming laxatives may increase the risk of bowel obstruction in patients with impaired GI motility.

Prescription Medications: Methylnaltrexone Relistor is a peripherally acting antagonist of the mu-opioid receptor. Methylnaltrexone is given subcutaneously, and dosing is weight based. Patients should be advised about the possibility of dizziness, abdominal pain, flatulence, and diaphoresis. This includes using an alternative opioid agent or a different route of administration. Switching to a transdermal or parenteral route of administration, as opposed to the oral route, may partially alleviate symptoms if the opioid has a direct local effect.

Opioids can be useful agents when managing acute and chronic pain, but they carry a risk of side effects. These effects can be debilitating and may result in discontinuation of the medication if they are not properly managed; therefore, patients should be counseled extensively about possible side effects and how to manage them properly. Side effects may be prevented or lessened if patients take appropriate nonpharmacologic measures such as proper hydration and dietary intake, physical activity, and establishment of a toileting routine.

Pharmacists are an excellent resource for guiding patients to appropriate OTC medications. Proper education and preventive measures regarding possible side effects of opioid analgesics can lead to improved medication adherence and quality of life.

Pain management. Pharmacotherapy: A Pathophysiologic Approach. Curtailing diversion and abuse of opioid analgesics without jeopardizing pain treatment. Boyer EW. Management of opioid analgesic overdose. N Engl J Med. Opioids, analgesia, and pain management. Satyavan K, Barna MM. Managing opioid-induced constipation. Pharmacy Times. Accessed August 20, Swegle JM, Logemann C. Management of common opioid-induced adverse effects. In addition, package inserts provided pharmacologic data and dose recommendations as needed.

Nausea often precedes vomiting, although they can occur separately. Many patients receiving opioids rate the nausea and vomiting as worse than their pain. Effective management of pain has an impact on clinical course and often depends on achieving an acceptable balance between opioid efficacy, safety, and tolerability.

Common opioid-related adverse events such as nausea and vomiting are associated with an overall lower achievement of effective pain management and patient satisfaction. However, in practice, clinicians employ various strategies to maximize efficacy, minimize these adverse effects, and ensure the careful, judicious, and evidence-based use of opioids for patients who require them.

Little research has been undertaken in recent years to develop opioid-sparing analgesics with improved risk—benefit profiles, despite the known need for agents such as these.

In some cases, opioid-sparing adjuvant analgesics are used to allow opioid dose reduction, but this is far from an ideal solution [64]. However, nonpharmacological interventions that specifically target cognitive processes may be effective in conjunction with analgesia for patients with chronic pain. Thus, a recent study of patients' perception of chronic pain showed that treatment effects can be enhanced by interventions that specifically target cognitive processes i.

Research has led to the development of several new types of opioid-based analgesic therapy, of which, some have been specifically designed to limit adverse events. Novel preparations of opioids, such as the transdermal fentanyl patches, achieve controlled transcutaneous opioid delivery by means of a fentanyl reservoir located behind a rate-controlling membrane.

Constipation, nausea, and vomiting remain the most frequent adverse events with this system, although it has been associated with lower incidences of constipation when compared with systemic applications of morphine in open-label studies [66—69]. However, there were no differences found between the incidences of nausea and vomiting [66,68,70,71]. When transdermal delivery systems were evaluated against orally and intrathecally delivered opioids in a recent systematic review of long-term opioid therapy for chronic noncancer pain, intrathecal opioids achieved the lowest rates of withdrawals from clinical studies due to adverse events [72].

However, it is worth noting that intrathecal drug delivery is not practical for many patients. One new therapeutic strategy has been to develop peripherally acting opioid receptor antagonists in order to selectively inhibit peripheral mu opioid receptors in the GI tract without reversing centrally mediated opioid-induced analgesia. Two new peripherally acting mu opioid antagonists, alvimopan and methylnaltrexone, have recently been approved by the FDA for the reduction of opioid-induced bowel dysfunction associated with opioid analgesics [73,74].

Although results of preliminary studies are promising, a recent systematic review of these agents for the relief of opioid-related constipation concluded that there are, as yet, not enough data to determine whether or not they are effective for this purpose [75].

One concern, however, is that antiemetic agents with a restricted ability to cross the blood-brain barrier may have a reduced efficacy against nausea and vomiting mediated through central mechanisms. Also under current investigation are oral fixed combinations of opioid receptor agonists and antagonists such as prolonged-release oxycodone and naloxone, as well as oxycodone and naltrexone [76,77].

These drugs are similarly designed to reduce peripheral GI side effects by their peripheral inhibitory action on gut opioid receptors [78]. However, although these agents have a low systemic bioavailability, a negative impact on the analgesic effects of the combination products by the antagonist component cannot be excluded [79].

The combination potentially offers less dosing flexibility than the use of separate antagonists. A novel approach is to combine more than one analgesic principle in one molecule so that both mechanisms are pharmacologically engaged. This concept was realized in tapentadol, a compound purposely designed to combine two analgesic actions, mu opioid receptor agonist activity with norepinephrine reuptake inhibition.

In this case, the analgesic effect is not reliant solely on agonist activity at the mu receptor that is also responsible for side effects. Data from preclinical studies indicate that the combination of these two analgesic actions is less likely to produce opioid-mediated side effects; for example, in one of the most commonly used emesis model species, the ferret [80] , tapentadol may produce fewer episodes of retching and vomiting as compared with morphine [81].

This suggests a potential therapeutic advantage over the currently available classical opioid analgesics, offering improved tolerability and equivalent analgesic efficacy. In conclusion, opioids cause nausea and vomiting in many patients through multiple and complex causative mechanisms. Nausea and vomiting are common side effects of opioid analgesia, and are distressing to patients, leading to a significant reduction in their quality of life. These types of side effect are often difficult to treat, can be persistent, and are major causes of noncompliance with pain relief medication.

Moreover, addressing such problems is associated with a cost burden to health care services. New approaches designed to address the clear therapeutic need may offer potential solutions to improve analgesic efficiency while diminishing the potential for adverse effects, especially nausea and vomiting, which lead to inadequate pain relief.

Survey of chronic pain in Europe: Prevalence, impact on daily life, and treatment. Eur J Pain ; 10 : — Google Scholar. Chronic pain in Australia: A prevalence study. Pain ; 89 : — Epidemiology of chronic non-malignant pain in Denmark. Pain ; : — 8. New perspectives on the management of diabetic peripheral neuropathic pain. Diab Vasc Dis Res ; 3 : — Prevalence of pain in the Spanish population: Telephone survey in homes. Eur J Pain ; 6 : — The burden of neuropathic pain: Results from a cross-sectional survey.

Critical issues on opioids in chronic non-cancer pain: An epidemiological study. Pain ; : — 9. OPEN Minds. The white paper on opioids and pain: a pan-European challenge ; How effective is long-term opioid therapy for chronic noncancer pain? Clin J Pain ; 23 : — 2. Portenoy RK. Opioid therapy for chronic nonmalignant pain: A review of the critical issues. J Pain Symptom Manage ; 11 : — Nicholson B. Responsible prescribing of opioids for the management of chronic pain. Drugs ; 63 : 17 — Harris J-D.

Management of expected and unexpected opioid-related side effects. Clin J Pain ; 24 : S8 — Cherny NI. Opioid analgesics: Comparative features and prescribing guidelines. Drugs ; 51 : — Comparative efficacy and safety of long-acting oral opioids for chronic non-cancer pain: A systematic review. J Pain Symptom Manage ; 26 : — Differences in the prevalence and severity of side effects based on type of analgesic prescription in patients with chronic cancer pain.

J Pain Symptom Manage ; 33 : 67 — Prevalence of opioid adverse events in chronic non-malignant pain: Systematic review of randomised trials of oral opioids.

Arthritis Res Ther ; 7 : R — Intravenous ondansetron for the control of opioid-induced nausea and vomiting. Clin Ther ; 21 : — Hornby PJ. Central neurocircuitry associated with emesis. Rousseau P. Nonpain symptom management in terminal care. Clin Geriatr Med ; 12 : — Management of opioid-induced gastrointestinal effects in patients receiving palliative care.

Pharmacotherapy ; 22 : — Textbook Of Medical Physiology , 11th edition. Philadelphia : Elsevier Saunders ; Google Preview. The endogenous opioid system and clinical pain management. Pharmacological characterization of the cloned kappa-, delta-, and mu-opioid receptors. Mol Pharmacol ; 45 : — 4. Emetic and antiemetic properties of regulatory peptides. Biull Eksp Biol Med ; : — 8.