The treatment depends on the cause of acute pericarditis, the person's strength and the presence of pericardial effusion, myocarditis or circulatory failure. In an 1866 answer, rest, relief of pain and repeated assessment of the heart are more defensible starting points than an indiscriminate attempt to suppress every sign of inflammation by depletion.
The bedside assessment would include the history of rheumatic illness, chest pain, a pericardial friction rub, the character of the pulse, breathing, the extent of cardiac dullness on percussion and changes in the heart sounds. Serial examination matters: disappearance of a pericardial friction rub need not mean recovery if fluid is separating the inflamed surfaces. Increasing oppression of breathing, weakness or a failing pulse would require reconsidering both the disease and the treatment. Auscultation with a stethoscope and careful repeated percussion supplied information that modern imaging now refines.
Period practice included local bloodletting with medicinal leeches, counterirritation with a blistering agent, opium for pain and rest, and disputed Mercury treatment intended to alter inflammatory exudation. A robust adult early in an apparently vigorous inflammatory attack was treated differently by depletion advocates from an exhausted person with anaemia, previous blood loss or advanced kidney disease. Even in that framework, a rapid weak pulse was not a command to remove more blood. Nor was Mercury an uncontested standard: a medical address published in December 1866 specifically listed its use in pericarditis among unresolved therapeutic questions.[ref]
Introductory Address at the Public Opening of the Medical Session, 1866–67 by William Tennant Gairdner. p. 294, therapeutic uncertainties concerning mercury in pericarditis and diuretics in Bright's disease
Modern correction: establish the diagnosis, identify complications and use cause-directed treatment rather than bloodletting or mercurialization. Electrocardiography, inflammatory markers, troponin where myocardial injury is suspected and echocardiography help distinguish uncomplicated pericarditis from important associated disease. A typical uncomplicated inflammatory episode is treated with aspirin or a suitable nonsteroidal anti-inflammatory drug, usually with colchicine and appropriate gastroprotection. Renal impairment, gastrointestinal bleeding, interactions and a specific infectious or systemic cause can modify this plan. Corticosteroids have selected indications and are not the routine first choice. Activity is restricted during active disease and return to exertion follows reassessment.[ref]
2025 ESC Guidelines for the management of myocarditis and pericarditis. Diagnostic assessment; section 6.2.2, pharmacological therapy for pericarditis
A large pericardial effusion requires attention to its haemodynamic effect, not merely its size. Cardiac tamponade requires urgent specialist drainage and stabilization. Purulent disease requires treatment of the infection and drainage; associated myocarditis or a systemic cause changes management further.[ref]
2025 ESC Guidelines for the management of myocarditis and pericarditis. Pericardial effusion and cardiac tamponade management pathways
These distinctions explain why treatment cannot be fixed solely by the label “acute”.Opium was chiefly used to relieve pain, procure sleep, suppress troublesome cough and restrain diarrhoea; each effect can relieve suffering while also creating a hazard. It is a mixture of alkaloids, not a single standardized modern drug. Preparations such as laudanum cannot be treated as interchangeable volumes of “a sedative”. Morphine and codeine account for important pharmacological effects, but historical extracts varied.
For pain, the useful objective is relief sufficient for rest and function. A person exhausted by severe pain may sleep after analgesia; that is different from using ever-increasing sedation to suppress an unexplained illness. In an 1866 explanation, opium might therefore accompany treatment of painful inflammatory disease or severe colic. It could palliate suffering even when no curative treatment existed. It did not follow that a quieter person had recovered from pericarditis, obstruction or infection.
For cough, reducing an exhausting, unproductive symptom was the historical aim. But suppressing a protective cough where clearance of secretions or maintenance of breathing is already impaired can be harmful. For diarrhoea, slowing intestinal transit reduces the number of stools; it does not restore lost fluid or eliminate an infectious cause. The modern pharmacological description of opium tincture specifically links its antidiarrhoeal effect to altered intestinal motility and greater absorption of water from intestinal contents.[ref] Reduced output is therefore not by itself proof that the underlying disease is improving.
Historical uses also extended to spasmodic disorders and states called nervous excitement. These broad categories mixed different causes. A drug producing drowsiness could conceal deterioration, and neither tetanus nor alcohol withdrawal becomes adequately treated merely because the person is less visibly agitated. The contemporary medical debate openly questioned when opium was useful in such different conditions as delirium tremens, dysentery and cholera.[ref]
Introductory Address at the Public Opening of the Medical Session, 1866–67 by William Tennant Gairdner. p. 294, disputed indications for opium in delirium tremens, dysentery and cholera
Modern correction: use a defined drug for a defined indication, with monitoring of benefit and toxicity. Properly prescribed opioids remain important for selected severe pain and palliation; crude opium is not a general remedy for sleeplessness, agitation or an undiagnosed abdomen. Major hazards include respiratory depression, excessive sedation, nausea, constipation, physical dependence and harmful interactions with other depressant drugs. Extra care is needed with renal or hepatic impairment. Gastrointestinal obstruction, particularly paralytic ileus, and significant respiratory compromise can preclude routine opioid use; the details depend on the drug and clinical setting.[ref]
Morphine by MedlinePlus. Important warning; precautions and adverse effects
[ref]Morphine Sulfate prescribing information (FDA). Contraindications; respiratory depression, gastrointestinal effects and special-risk groups
In sustained palliative treatment, review analgesia and adverse effects and anticipate constipation, rather than waiting for it to become severe.[ref]