= Solution
\b[There is no single reliably poisonous dose for each <opium> preparation. Identify the preparation and exposure, but diagnose and treat poisoning from its effects, especially depressed breathing.] Toxicity depends on the actual alkaloid content, route, age, <opioid tolerance>, coexisting illness and other depressants. A quantity tolerated by one person may produce dangerous <respiratory depression> in another. In particular, neither a historical ordinary dose nor a published fatal quantity defines a boundary below which every person is safe.<Opioid overdose by WHO>[Risk factors and the characteristic combination of impaired consciousness, depressed breathing and pinpoint pupils]{ref}
For the historical numerical part, separate formulation strength from a poisonous threshold. The relevant British formulations are those associated with the <British Pharmacopoeia by the General Medical Council (1864)>, not a later edition or the bracketed American recipes in <The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865)>. In the following comparisons, a <grain> is a mass unit and a <minim> a volume unit; a fluid ounce is 480 <minims>. These comparisons describe period preparations and are not administration instructions.
* <Opium tincture> and the 1864 <Vinum Opii> are each described as containing the soluble constituents of one grain of dry <opium> in approximately 14½ minims. <Tinctura Camphorae cum Opio> contains one grain in half a fluid ounce, or 240 minims. Confusing these liquids therefore creates a large error in exposure.
* <Extractum Opii> is an aqueous extract with potency dependent on extraction and starting material. The contemporary comparison gives about half a grain of dry extract as equivalent to one grain of raw <opium>. <Extractum Opii Liquidum> contains about one grain of extract in 22 minims. This is an approximate raw-drug equivalence, not an assay of <morphine>.
* <Pilula Opii> contains one part <opium> in five parts pill mass; <Pilula Plumbi cum Opio> one in eight. The latter also carries the independent hazard of a <lead> compound.
* <Pulvis Ipecacuanhae cum Opio>, <Pulvis Kino cum Opio> and <Pulvis Cretae Aromaticus cum Opio> contain one part <opium> in ten, twenty and forty parts respectively. Other ingredients do not abolish <opioid> toxicity.
These strengths make clear how to compare exposures once their quantities are known. For example, if a preparation contains a mass fraction $f$ of dry <opium> and a mass $m$ of it was taken, its nominal raw-drug content is
$$
\boxed{m_{\mathrm{opium}}=fm.}
$$
That equation cannot supply an unknown toxic threshold or account for all differences in absorption.<The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865)>[Posological Table, final Opium comparison: British strengths and approximate extract equivalence]{ref}
Two entries require explicit textual caution. The monograph for <Trochisci Opii> specifies 72 grains of <Extractum Opii> divided into 720 lozenges, hence \b[one tenth of a grain of extract per lozenge]; its summary table instead says one tenth of a grain of <opium>. Those are not interchangeable descriptions. Similarly, the <Enema Opii> recipe specifies 30 minims of <opium tincture> with two fluid ounces of starch decoction, whereas the summary table describes one grain of <opium> in two fluid ounces. At the stated tincture strength the recipe contributes about two grains to the mixture, so the discrepancy should not be silently turned into a precise rectal poisonous dose.<The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865)>[Papaverceae, Parts 2–3: Enema Opii recipe and Trochisci Opii recipe; compare Posological Table]{ref}
The external preparations also belong to the officinal list: <Emplastrum Opii>, <Linimentum Opii> and <Unguentum Gallae cum Opio>. The plaster contains one part powdered <opium> to nine parts resin plaster; the liniment mixes equal volumes of <opium tincture> and soap liniment. The galls ointment is described as approximately one part <opium> in 14½ parts of ointment. These are not oral medicines. Exposure over damaged skin, contact with mucosa or accidental swallowing cannot be evaluated by assigning a universal number of spoonfuls or applications.<The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865)>[Papaverceae, Part 2: plaster and liniment; Part 3: galls and opium ointment]{ref}
If preparations derived from the purified alkaloid are included, distinguish them from raw <opium>: <Liquor Morphiae Hydrochloratis> contains four grains of <morphine hydrochloride> per fluid ounce; <Suppositoria Morphiae> contain a quarter grain each; <Trochisci Morphiae> and <Trochisci Morphiae et Ipecacuanhae> contain one thirty-sixth of a grain of the salt per lozenge. A raw-drug fraction is not the same thing as a mass of purified <morphine hydrochloride>.<The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865)>[Papaverceae, Part 3, Of Hydrochlorate of Morphia: solution, suppositories and the two lozenges]{ref}
Deep historical narcotism means profound <opioid poisoning>, with depressed <consciousness> and dangerously slow or ineffective breathing, often with small <pupils>. Current priorities are emergency help, an open <airway>, assisted ventilation and <oxygen therapy> as required, and prompt <naloxone>. If there is <cardiac arrest>, start appropriate <cardiopulmonary resuscitation>. Repeat <naloxone> or use an infusion when clinically required, and continue observation because the <opioid> may outlast the reversal. A transient awakening is not proof of sustained recovery.<Opioid overdose by WHO>[Emergency responses: basic life support and timely naloxone]{ref}<Responding to a Suspected Opioid Overdose by the National Institute for Occupational Safety and Health>[Emergency response, naloxone and continuing assistance]{ref}
Older attempts to empty the <stomach> or to rouse an unconscious person must not displace respiratory support. Do not give oral drinks or an <emetic> to an unconscious person, and do not perform unprotected gastric instrumentation: <aspiration> can add a second cause of respiratory failure. The concise therapeutic answer is therefore \b[support ventilation and reverse the <opioid> effect, rather than waiting for a calculated poisonous dose to be exceeded].
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