Original teaching video 临床小白系列：呕吐的处理-除了胃复安，还有什么_哔哩哔哩_bilibili
Causes of Vomiting
- Reflex vomiting is often caused by gastrointestinal diseases, hepatobiliary and pancreatic diseases, peritoneal and mesenteric diseases, kidney diseases, glaucoma, etc.
- Central vomiting:
- Nervous system diseases such as intracranial infections, epilepsy, cranial trauma, etc.
- Systemic diseases such as uremia, thyroid storm, hypoglycemia, hyponatremia, early pregnancy, etc.
- Drugs such as chemotherapy agents, morphine, etc.
- Poisoning and psychological factors.
- Vestibular disorder vomiting, caused by benign paroxysmal positional vertigo (BPPV), labyrinthitis, motion sickness, etc.
Classification of Anti-Emetic Drugs
Anti-emetic drugs work by affecting different aspects of the vomiting reflex, including serotonin (5-HT3) receptor antagonists, prokinetic agents, acid suppressants, glucocorticoids, anticholinergic drugs, NK-1 receptor antagonists.
| Site of Action | Drugs |
|---|---|
| Cortex | Benzodiazepines |
| Chemoreceptor Trigger Zone | Phenothiazines, butyrophenones, 5-HT3 receptor antagonists, NK-1 receptor antagonists, benzamide derivatives |
| Vomiting Center | Antihistamines, anticholinergics |
| Visceral Afferent Nerves | 5-HT3 receptor antagonists, benzamide derivatives |
| Others | Glucocorticoids, opioid receptor antagonists, acid suppressants, prokinetic agents, psychotropic drugs, vitamin B6 |
| Category | Drugs | Precautions |
|---|---|---|
| Benzodiazepines | Alprazolam, etc. | High risk of falls, especially during the first 2 weeks of use. |
| Phenothiazines | Promethazine, chlorpromazine, prochlorperazine, etc. | Chlorpromazine can cause vasodilation, hypotension, deep sedation, and somnolence. |
| Butyrophenones | Haloperidol, droperidol | High doses of haloperidol may cause QT interval prolongation, torsades de pointes, sedation, extrapyramidal symptoms. |
| 5-HT3 Receptor Antagonists | Ondansetron, tropisetron, granisetron, azasetron, dolasetron, palonosetron | Adverse reactions include headache, constipation, elevated transaminases, dizziness. Ondansetron, granisetron, and dolasetron may cause QT prolongation and potentially fatal arrhythmias. |
| NK-1 Receptor Antagonists | Aprepitant, fosaprepitant, rolapitant | ① NK-1 receptor antagonists selectively block NK-1 receptors in the brain, antagonizing substance P. ② Common adverse effects include fatigue, weakness, and belching. Aprepitant is a CYP3A4 inhibitor, caution when co-administered with drugs metabolized primarily or partially by CYP3A4. |
| Benzamide Derivatives | Metoclopramide (Reglan) | Adverse effects include extrapyramidal symptoms and drowsiness. |
| Antihistamines | Diphenhydramine, promethazine, hydroxyzine, doxylamine, etc. | May cause drowsiness, somnolence, and extrapyramidal symptoms. |
| Anticholinergics | Scopolamine patch, diphenidol hydrochloride, etc. | Adverse effects include dry mouth, urinary retention, anxiety, and blurred vision. |
| Glucocorticoids | Dexamethasone, etc. | May increase blood sugar in diabetic patients. |
| Opioid Receptor Antagonists | Naloxone, methylnaltrexone | Used for opioid-induced vomiting. |
| Acid Suppressants | Proton pump inhibitors (PPIs): omeprazole, pantoprazole, lansoprazole, rabeprazole, esomeprazole (esomeprazole) |
Adverse effects include headache, diarrhea, nausea, gastrointestinal bloating, abdominal pain, constipation, headache, and rare severe reactions such as anaphylactic shock, pancytopenia, vasculitis, lupus erythematosus, interstitial nephritis, bronchial asthma, musculoskeletal pain, and even rhabdomyolysis. |
| H2 receptor antagonists: cimetidine, ranitidine, famotidine, etc. | Adverse effects include dizziness, drowsiness, disorientation, male breast enlargement and feminization, galactorrhea in females. Long-term use may cause bacterial overgrowth in the stomach and lead to infections. | |
| Prokinetics | Domperidone (Motilium), mosapride, cisapride, itopride | 1. Domperidone is a selective peripheral dopamine D2 receptor antagonist; cases of sudden cardiac death and severe arrhythmia reported abroad. 2. Cisapride selectively acts on the postganglionic neurons of the enteric nervous system to promote acetylcholine release; itopride is a dopamine D2 receptor antagonist and acetylcholinesterase inhibitor. |
| Psychotropic Drugs | Olanzapine, mirtazapine, lorazepam | Olanzapine adverse effects include drowsiness, orthostatic hypotension, and constipation. |
Nitopitant and palonosetron, brand name Akynzeo
Common Vomiting and Corresponding Management
- Gastrointestinal reactions (vomiting gastric contents, dry retching, vomiting gastric juice)
- Metoclopramide (Reglan) 1 vial intramuscular injection (acts on visceral afferent nerves) + oral or IV PPI suitable for drug reactions including chemotherapy, postoperative vomiting, gastroenteritis, etc.
- Contraindications:
- Avoid concurrent use with drugs that may cause extrapyramidal reactions (common adverse effects).
- Gastrointestinal bleeding, mechanical intestinal obstruction, or perforation (drug may increase gastrointestinal motility).
- Not suitable for vomiting in breast cancer patients due to chemotherapy or radiotherapy (metoclopramide can reduce hypothalamic release of prolactin-inhibiting factors, increasing prolactin secretion, accelerating cell cycle and promoting breast cancer cell metastasis; best avoided after breast cancer surgery).
- Domperidone (Motilium) also contraindicated in breast cancer.
- Use tropisetron, scopolamine, etc., when metoclopramide is ineffective or contraindicated.
- Metoclopramide (Reglan) 1 vial intramuscular injection (acts on visceral afferent nerves) + oral or IV PPI suitable for drug reactions including chemotherapy, postoperative vomiting, gastroenteritis, etc.
-
- Massive gastrointestinal bleeding (even perforation)—dark red stools, hematemesis (exclude esophageal and gastric variceal bleeding caused by cirrhosis)
- Use anti-emetic drugs with caution; treating the primary disease is key.
- Digestive ulcer bleeding esomeprazole 808 protocol: IV injection of 80 mg, then 8 mg/hour maintenance for 72 hours (3 days), then adjusted to 40/80 mg once or twice daily depending on the situation.
- Perforation: emergency surgery; conservative treatment not recommended, some hospitals use 40 mg every 6 hours via micro-pump.
- Vomiting caused by pyloric obstruction (vomiting gastric contents immediately after eating, relieved after vomiting)
- Edematous type: gastric tube placement + PPI, wash stomach with 1.5-3% hypertonic saline (can clamp gastric tube for 1 hour after instillation in ward).
- Scar type: gastric tube placement + PPI, surgery.
- Metoclopramide and anisodamine can slightly relieve symptoms but are symptomatic treatments.
- Special case: gastrointestinal dysfunction nausea and vomiting, such as postoperative gastric paresis — gastric tube placement, then metoclopramide, PPI, mosapride.
- If vomiting persists, use tropisetron and other 5-HT receptor antagonists; acupuncture from hospital acupuncture department can also be tried if available.
- Vomiting caused by mechanical intestinal obstruction
- Determine obstruction site: standing abdominal plain film, full abdominal CT scan, physical examination.
- Check blood supply issues: ① Strangulated intestinal obstruction—bloody stools, peritonitis requires emergency surgery; ② mesenteric arterial embolism—severe symptoms but mild signs, history of atrial fibrillation, elevated D-dimer.
- Differentiate from paralytic ileus: hypokalemia, perforation.
- Use spasmolytic and analgesic drugs cautiously to avoid masking diagnosis; treat primary disease after diagnosis.
- General treatment process: fasting, gastrointestinal decompression (gastric tube + enema), fluid and electrolyte supplementation, PPI gastric protection, somatostatin/octreotide, antibiotics.
- Vomiting caused by dizziness (try to treat underlying dizziness disease)
- ① Motion sickness, migraine, etc.: anticholinergics, antihistamines can treat motion sickness vomiting; scopolamine, diphenidol hydrochloride, diphenhydramine, meclizine, promethazine, etc. (Note: do not medicate after a single vomiting episode, but if symptoms persist).
- ② Intracranial hypertension: projectile vomiting, neck stiffness, papilledema: use mannitol + 50% glucose alternating dehydration, steroid pulse therapy, gastric protection; treating the cause is critical.
- ③ Cervical spondylosis causing dizziness and vomiting: spinal type: mannitol + steroids + gastric protection; nerve root type: NSAIDs + gastric protection.
- ④ Benign paroxysmal positional vertigo: sudden onset, first use metoclopramide, oral betahistine, neurology consultation for repositioning maneuvers for BPPV.
Chemotherapy-Induced Vomiting and Corresponding Management
Mechanism is complex; prevention depends on patient’s past chemotherapy response and whether regimen is highly emetogenic; preventive dual or triple therapy before chemotherapy.
- First step: before chemotherapy, use dexamethasone, diphenhydramine, tropisetron/ondansetron. If vomiting occurs, add metoclopramide (contraindicated in breast cancer).
- Second step: before chemotherapy, use dexamethasone/diphenhydramine + tropisetron/ondansetron dual therapy; if vomiting occurs, add metoclopramide (contraindicated in breast cancer).
- Third step: before chemotherapy, triple therapy with dexamethasone + tropisetron/ondansetron + aprepitant.
Aprepitant and other NK-1 receptor antagonists are new drugs.