Palliative Care Pharmacology
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Direct answer
Palliative pharmacology is built on a short list of inexpensive drugs prescribed with precision: oral morphine for pain (starting 2.5-5 mg every four hours, titrated), senna or bisacodyl from the first opioid dose, metoclopramide or haloperidol for nausea, haloperidol for delirium, and subcutaneous midazolam and hyoscine for terminal restlessness and secretions. The breakthrough rule is arithmetic — one-sixth of the total daily morphine dose, available on demand. When swallowing fails, drugs convert to continuous subcutaneous infusion via a syringe driver. The route and dose adjust, the intent does not: symptoms are treated to a goal the patient defines. In India this discipline rides on a legal reform — the 2014 amendment that made oral morphine genuinely accessible after decades of licence-driven scarcity.
What you must remember
- Oral morphine start: 2.5-5 mg every four hours in opioid-naive adults (lower in the elderly), with breakthrough doses of one-sixth the total daily dose, repeated up to hourly if needed.
- Laxatives are not optional: tolerance never develops to opioid-induced constipation — prescribe senna or bisacodyl with every opioid, and macrogols where fluids allow.
- Nausea by cause: gastric stasis — metoclopramide 10 mg three times daily; chemical causes (hypercalcaemia, opioids) — haloperidol 0.5-1.5 mg at night; raised intracranial pressure — cyclizine or dexamethasone.
- Delirium and agitation: haloperidol 0.5-2.5 mg, titrated; midazolam 2.5-5 mg subcutaneously for terminal restlessness after non-drug measures fail.
- Death rattle: hyoscine butylbromide 20 mg subcutaneously, repeated or infused, plus repositioning and family explanation — treating the family's distress as much as the patient's.
- Renal failure rewrites the chart: morphine-6-glucuronide accumulates — favour fentanyl or buprenorphine, or halve intervals with care.
- Syringe driver conversions: morphine to subcutaneous at roughly half the oral dose; diamorphine where used converts one-to-one with morphine subcutaneously.
- The Indian legal fact: the 2014 Narcotic Drugs amendment designated morphine an essential narcotic drug with simplified licensing — the change that let palliative programmes outside Kerala finally stock morphine.
A worked end-of-life pathway
A 62-year-old with advanced lung cancer is admitted with bone and chest pain, taking oral morphine 20 mg six-hourly (120 mg daily) with inadequate relief. The pathway demonstrates the craft. Breakthrough morphine is set at one-sixth of 120 mg — 20 mg — and its use over 24 hours (say, four doses) is added forward: the new regular dose becomes 40 mg six-hourly. Senna continues nightly, metoclopramide covers opioid nausea, and dexamethasone 8 mg may be added for liver-capsule or bone pain as an adjuvant. When he can no longer swallow, the total oral morphine converts to subcutaneous infusion at about half the oral dose, combined in the syringe driver with midazolam for agitation and hyoscine for secretions. The family is told what each line is for — palliative prescribing succeeds only when it is explained.
Alongside all of it, the de-prescribing list: statins, antihypertensives, oral hypoglycaemics (sliding to symptom-guided care), and iron supplements all stop. Continuing futile drugs is not neutral — it adds pill burden, interactions and monitoring to a patient whose goals have changed.
How the exam frames it
The arithmetic questions are guaranteed: compute the breakthrough dose from the daily morphine total (one-sixth), or convert oral to subcutaneous (halve it). Mechanism matching follows: opioids cause constipation by gut mu-receptors with no tolerance — hence the mandatory laxative, a favourite one-liner. The renal-adjustment question separates strong candidates: morphine's glucuronide metabolites accumulate, so fentanyl becomes the renal-failure opioid. The Indian-context question is unique to this topic and nearly always surfaces: morphine availability, the National Programme for Palliative Care, and the 2014 amendment that fixed a regulatory problem killing pain relief — Kerala's community model (Neighborhood Network in Palliative Care) is quotable evidence that home-based morphine care works at scale in India. One ethical viva line completes the picture: increasing morphine for pain with documented assessment is titration, not euthanasia — the doctrine of double effect applied honestly.
Frequently asked questions
How is a breakthrough morphine dose calculated?
One-sixth of the total daily opioid dose, given on demand, with the doses used folded into the next day's regular prescription.
Why must a laxative accompany every opioid?
Tolerance does not develop to opioid-induced constipation, so prevention with senna or bisacodyl starts with the first dose.
Which opioid is preferred in renal failure?
Fentanyl (or buprenorphine), because morphine's active metabolites accumulate in renal impairment and cause toxicity.
What drugs go into a terminal syringe driver?
Typically an opioid plus midazolam for restlessness, haloperidol for delirium or nausea, and hyoscine butylbromide for respiratory secretions, combined per compatibility rules.
What changed for morphine access in India in 2014?
The Narcotic Drugs and Psychotropic Substances amendment recognised morphine as an essential narcotic drug and simplified licensing, allowing hospitals countrywide to stock oral morphine.