Aminophylline
Contraindicated
Textbook
Should not be mixed in the same infusion bottle/syringe.
Do not mix.
Source: KDT 7e · p227
Drug reference
Morphine
Opioid analgesic (phenanthrene, mu-agonist) · Analgesic
Also known as Morphine Sulfate, Morphine Hydrochloride, MST Continus, Kadian, Avinza, Roxanol
START
Opioid-naïve: 2.5–10 mg IV/SC titrated or 5–10 mg oral IR q4h; reduce in elderly/renal/hepatic
TYPICAL MAX
No absolute ceiling in titrated cancer pain; titrate to effect/safety with monitoring
STOP IF
Respiratory depression (naloxone), severe hypotension, ileus, signs of toxicity in renal failure
WATCH
Respiratory rate/sedation (esp. with other CNS depressants), bowel regimen, renal function, misuse; naloxone available
CDSCO approvedSchedule H (also under Narcotic Drugs and Psychotropic Substances Act, 1985)ATC N02AA01
KDIGO 2024 + manufacturer label
- ONSET
- 5min · IV onset (~5 min)
- PEAK
- 20min · IV peak (~20 min)
- t½
- 3h · plasma t½
- DURATION
- 4h · IR analgesia
EXCRETION
Hepatic glucuronidation; ~90% renal glucuronides
route + CYP
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
Use only if clearly needed — neonatal opioid withdrawal/respiratory depression with prolonged or peripartum use
FDA category + note
Top interactionssee all 12 →
- AminophyllineContraindicatedTextbookKDT 7e · p227
- MaoisContraindicatedDatabaseKimi deep-research + Cla
- ChlorpromazineSevereTextbook-citedKDT 7e · p950
- DiazepamSevereTextbook-citedKDT 7e · p950
Available in India
20 branded formulations and 2 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Mechanism
Agonist at mu (and kappa) opioid receptors in CNS/periphery — inhibits ascending nociceptive transmission and alters pain perception; also venodilation/preload reduction and respiratory-centre depression.
Indications
Moderate–severe acute painChronic cancer/palliative painAcute pulmonary oedema/MI pain (adjunct)Dyspnoea in palliative care
Dosing
- Adult
- Opioid-naïve acute: 2.5–10 mg IV/SC/IM titrated, or 5–10 mg oral IR every 4 h; modified-release for chronic pain after titration. Individualise; lower in elderly/frail.
- Pediatric
- 0.05–0.1 mg/kg IV titrated; oral per weight (specialist).
- Renal adjustment
- Active metabolite M6G accumulates in renal impairment — reduce dose/extend interval; consider alternative opioid in severe impairment.
- Hepatic adjustment
- Reduce dose/frequency (reduced clearance, encephalopathy risk).
- Geriatric
- Reduce starting dose ~25–50%; titrate slowly.
- Max dose
- No absolute ceiling in titrated cancer pain; acute/opioid-naïve titrate carefully to effect/safety
Pharmacokinetics
Onset
IV ~5 min; oral IR ~30 min
Peak effect
IV ~20 min; oral IR 1 h
Duration
IR 3–4 h; MR 12–24 h
Half-life
~2–4 h (M6G longer, esp. renal impairment)
Bioavailability
Oral ~20–40% (high first-pass)
Protein binding
~30–35%
Metabolism
Hepatic glucuronidation → M3G (inactive/neuroexcitatory) and M6G (active analgesic)
Excretion
Renal (~90%, mainly glucuronides)
Contraindications
- Acute/severe respiratory depression
- Acute or severe bronchial asthma (uncontrolled, unmonitored)
- Paralytic ileus / known/suspected GI obstruction
- Concurrent or recent (14 days) MAOI
- Hypersensitivity to morphine
Side effects
Common
Constipation (persistent)Nausea/vomitingSedation/drowsinessPruritusMiosis, urinary retention
Serious
- Respiratory depression (potentially fatal — esp. with other CNS depressants)
- Severe hypotension
- Dependence/addiction, tolerance, withdrawal
- Neurotoxicity/myoclonus (M3G, renal failure)
- Serotonin syndrome (with serotonergics/MAOI); adrenal insufficiency (chronic)
Pregnancy & lactation
Pregnancy
Use only if clearly needed — neonatal opioid withdrawal/respiratory depression with prolonged or peripartum use
Lactation
Occasional low doses with monitoring may be acceptable; avoid repeated/high dose (infant sedation/apnoea)
Drug interactions
Maois
Contraindicated
Database
Severe, sometimes fatal reaction (excitatory or hypotensive)
Avoid within 14 days of an MAOI
Source: Kimi deep-research + Cla
Chlorpromazine
Severe
Textbook-cited
Excessive sedation and respiratory depression; potentially fatal.
Avoid concurrent use
Source: KDT 7e · p950
Diazepam
Severe
Textbook-cited
Excessive sedation, respiratory depression, motor impairment.
Avoid concurrent use
Source: KDT 7e · p950
Imipramine
Severe
Textbook-cited
Excessive sedation and respiratory depression; potentially fatal.
Avoid concurrent use
Source: KDT 7e · p950
Acetaminophen
Severe
Textbook
Acetaminophen-related hepatotoxicity, a significant cause for liver failure.
Many practitioners have moved away from opioid-acetaminophen combination analgesics to avoid the risk of excessive acetaminophen exposure.
Source: Harrison 22e · p98-99
Barbiturates
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Chlordiazepoxide Hydrochloride
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Clomethiazole
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Clorazepate
Severe
Textbook
Increased number of deaths.
Avoid combination due to increased risk of respiratory depression and death.
Source: G&G 14e
Melatonin
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Neuroleptics
Severe
Textbook
Increased CNS depression, potentially leading to overdose symptoms.
Not explicitly stated
Source: KDT 7e
Related guidelines
Ask House about Morphine
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Harrison 22e, Katzung·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19