In poisoning with which substances is the use of apomorphine strictly contraindicated or ineffective?

Apomorphine is strictly contraindicated in oral poisoning with corrosive substances, such as strong acids or alkalis. This is due to the risk of causing secondary chemical burns to the mucosa of the esophagus and respiratory tract during the retrograde passage of the toxin.

Why is apomorphine administered subcutaneously?

Subcutaneous administration allows the drug to rapidly penetrate the CNS and stimulate $D_2$ receptors, ensuring a short latent period where vomiting occurs within 5–10 minutes.

Is apomorphine a pain reliever?

No. Despite being a semi-synthetic derivative of morphine, it lacks analgesic activity. Its primary effect is emetic.

Why is the drug contraindicated in peptic ulcer disease?

Intense vomiting movements sharply increase gastric pressure and cause muscular spasms, which can trigger ulcer perforation or gastrointestinal hemorrhage.

How is apomorphine eliminated from the body?

Elimination occurs in two steps: hepatic metabolism followed by renal excretion of the metabolites.

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Apomorphine

Apomorphini hydrochloridum

For medical students2 min readUpdated 2026-10-10

Apomorphine is a semi-synthetic alkaloid and a derivative of morphine. In pharmacology, it belongs to the group of drugs affecting the digestive system, specifically emetics. The main therapeutic goal of the drug is to rapidly induce vomiting via direct stimulation of the central nervous system.

Pharmacological GroupEmetics

MechanismDirect stimulation of $D_2$ receptors in the chemoreceptor trigger zone

Route of AdministrationSubcutaneous (latent period 5–10 minutes)

OriginSemi-synthetic morphine derivative

Mechanism of Action and Pharmacokinetics

Apomorphine acts as a centrally acting emetic. Its primary pharmacological target is the $D_2$ receptors of the chemoreceptor trigger zone (CTZ) of the vomiting center, exerting a direct stimulating effect upon them.

From a pharmacokinetic perspective, the drug is characterized by rapid penetration into the CNS. With standard subcutaneous administration, the latent period is very short: a pronounced emetic reflex occurs within just 5–10 minutes.

Elimination occurs in two stages: hepatic metabolism followed by renal excretion of the resulting metabolites.

Indications

In modern clinical practice, centrally acting emetics are rarely used; however, Apomorphini hydrochloridum has two specific clinical niches:

Acute Poisoning. Used for the emergency and rapid removal of poisons from the stomach. This is particularly relevant when traditional gastric lavage via a nasogastric tube is technically impossible or hindered for any reason.
Treatment of Chronic Alcoholism. In addiction medicine, the drug is used in aversion therapy. The principle relies on establishing a strong conditioned negative reflex to alcohol: the patient is given alcohol while under the influence of apomorphine, associating the taste and smell of alcohol with severe vomiting.

Contraindications

The act of vomiting is a severe physical stressor accompanied by a sharp increase in intrathoracic and intra-abdominal pressure, as well as significant muscular contraction. Consequently, apomorphine has several strict contraindications:

Severe heart disease (due to the risk of acute decompensation secondary to hemodynamic stress).
Active forms of tuberculosis and pulmonary hemorrhage (increased intrathoracic pressure can provoke or worsen profuse bleeding).
Peptic ulcer disease of the stomach and duodenum (intense antiperistaltic contractions create a risk of ulcer perforation or gastrointestinal bleeding).
Organic CNS lesions.

Formulations and Administration

The drug is available as a 1% solution in 1 mL ampoules. It is administered exclusively subcutaneously.

Adult Dosing:

Average therapeutic dose: 2–3 mg (0.002–0.003 g).
Maximum single dose (MSD): 5 mg (0.005 g).
Maximum daily dose (MDD): 10 mg (0.01 g).

Mnemonic

APOMORPHINE: Alkaloid, SUBCUTANEOUS — Immediate emetic reflex and no poisons left.

Frequently asked questions

In poisoning with which substances is the use of apomorphine strictly contraindicated or ineffective?: Apomorphine is strictly contraindicated in oral poisoning with corrosive substances, such as strong acids or alkalis. This is due to the risk of causing secondary chemical burns to the mucosa of the esophagus and respiratory tract during the retrograde passage of the toxin.
Why is apomorphine administered subcutaneously?: Subcutaneous administration allows the drug to rapidly penetrate the CNS and stimulate $D_2$ receptors, ensuring a short latent period where vomiting occurs within 5–10 minutes.
Is apomorphine a pain reliever?: No. Despite being a semi-synthetic derivative of morphine, it lacks analgesic activity. Its primary effect is emetic.
Why is the drug contraindicated in peptic ulcer disease?: Intense vomiting movements sharply increase gastric pressure and cause muscular spasms, which can trigger ulcer perforation or gastrointestinal hemorrhage.
How is apomorphine eliminated from the body?: Elimination occurs in two steps: hepatic metabolism followed by renal excretion of the metabolites.

Go deeper

Topography and physiology of the vomiting center and chemoreceptor trigger zone.
The role of $D_2$ receptors in the central nervous system.
Antiemetics (dopamine receptor antagonists: metoclopramide, domperidone).
Principles of emergency care for acute oral poisonings.
Mechanisms of aversion therapy in the treatment of substance dependencies.