Chapter 10 Analgesic Drugs Flashcards
Opioid Drugs
Synthetic drugs that bind to the opiate receptors to relieve pain
Opiod drug mild antagonists
codeine, hydrocodone
Opiod drug strong antagonists
morphine, hydromorphone, oxycodone, oxymorphone, meperidine, fentanyl, and methadone
Meperidine
not recommended for long-term use because of the accumulation of a neurotoxic metabolite, normeperidine, which can cause seizures
Opioid Ceiling Effect
-Drug reaches a maximum analgesic effect
-Analgesia does not improve, even with higher doses
Pentazocine
Nalbuphine
Agonists
- Bind to an opioid pain receptor in the brain
- Cause an analgesic response (reduction of pain sensation)
Agonists-Antagonists
- Bind to a pain receptor
- Cause a weaker neurologic response than a full agonist
- Also called partial agonist or mixed agonist
Antagonists
- Reverse the effects of these drugs on pain receptors
- Bind to a pain receptor and exert no response
- Also known as competitive antagonists
Opioid Analgesics Main Use
- to alleviate moderate to severe pain
- Often given with adjuvant analgesic drugs to assist primary drugs with pain relief
Opiods are also used for
- Cough center suppression
- Treatment of diarrhea
- Balanced anesthesia
Opioid Analgesics: Contraindications
Use with extreme caution in patients with:
- Respiratory insufficiency
- Elevated intracranial pressure
- Morbid obesity or sleep apnea
- Paralytic ileus
- Pregnancy
Opioid Analgesics: Adverse Effects
CNS depression Leads to respiratory depression Most serious adverse effect Nausea and vomiting Urinary retention Diaphoresis and flushing Pupil constriction (miosis) Constipation Itching
Opioids: Opioid Tolerance
- A common physiologic result of chronic opioid treatment
- Result: larger dose is required to maintain the same level of analgesia
Opioids: Physical Dependence
- Physiologic adaptation of the body to the presence of an opioid
- Opioid tolerance and physical dependence are expected with long-term opioid treatment and should not be confused with psychologic dependence (addiction)
Opioids: Psychologic Dependence
A pattern of compulsive drug use characterized by a continued craving for an opioid and the need to use the opioid for effects other than pain relief
Opioid Analgesics: Interactions
- Alcohol
- Antihistamines
- Barbiturates
- Benzodiazepines
- Monoamine oxidase inhibitors
- Others
Codeine Sulfate
- Natural opiate alkaloid (Schedule II) obtained from opium
- Less effective
- Ceiling effect
- More commonly used as an antitussive drug
- GI disturbance
Fentanyl
- Synthetic opioid (Schedule II) used to treat moderate to severe pain
- Fentanyl in a dose of 0.1 mg intravenously is roughly equivalent to 10 mg of morphine intravenously
Dilaudid
Hydromorphone (Dilaudid): very potent opioid analgesic; Schedule II drug
One milligram of IV or IM hydromorphone is equivalent to 7 mg of morphine
Methadone Hydrochloride (Dolophine)
- Synthetic opioid analgesic (Schedule II)
- Opioid of choice for the detoxification treatment of opioid addicts in methadone maintenance programs
- Renewed interest in the use of methadone for chronic (e.g., neuropathic) and cancer-related pain
- Prolonged half-life of the drug: cause of unintentional overdoses and deaths
- Cardiac dysrhythmias
Morphine Sulfate
- Naturally occurring alkaloid derived from the opium poppy
- Drug prototype for all opioid drugs; Schedule II controlled substance
- Indication: severe pain
- High abuse potential
- Oral, injectable, and rectal dosage forms; also extended-release forms
Naloxone Hydrochloride (Narcan)
- Pure opioid antagonist
- Drug of choice for the complete or partial reversal of opioid-induced respiratory depression
- Indicated in cases of suspected acute opioid overdose
- Failure of the drug to significantly reverse the effects of the presumed opioid overdose indicates that the condition may not be related to opioid overdose.
Opioid Analgesics:Nursing Implications
- Withhold dose and contact physician if there is a decline in the patient’s condition or if vital signs are abnormal, especially if respiratory rate is less than 10 to 12 breaths/min.
- Constipation is a common adverse effect and may be prevented with adequate fluid and fiber intake.
