# Guaifenesin (GGE): veterinary dose and monograph

> Guaifenesin (GGE) is a veterinary sedative or anaesthetic agent. Centrally acting skeletal-muscle relaxant given intravenously, used almost exclusively in LARGE ANIMALS to provide muscle relaxation during induction and as part of injectable field-anaesthesia "triple drip" combinations (guaifenesin +… Indications include muscle relaxation at induction of large-animal anaesthesia; component of "triple drip" total intravenous anaesthesia (with ketamine + xylazine) for field surgery; improving relaxation/recovery quality in equine and ruminant anaesthesia. This monograph lists 8 reference doses for dogs, cattle, horses, goats, sheep and camelids, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/guaifenesin · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Sedative / anaesthetic
- **Also known as:** GGE, Glyceryl guaiacolate, Guaiphenesin
- **Species with doses:** Dogs, Cattle, Horses, Goats, Sheep and Camelids
- **General dose range:** 50–100 mg/kg IV IV to effect (induction) — check the species tables for the indication
- **Routes:** IV, PO
- **Last reviewed:** 1 October 2026

## Indications

- Muscle relaxation at induction of large-animal anaesthesia
- Component of "triple drip" total intravenous anaesthesia (with ketamine + xylazine) for field surgery
- Improving relaxation/recovery quality in equine and ruminant anaesthesia

## Guaifenesin (GGE) dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Guaifenesin (GGE) doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Muscle relaxation — strychnine / tetanus | 110 mg/kg | IV | repeat as needed | — |
| Expectorant (oral) | 3–5 mg/kg | PO | q8h | — |

- Muscle relaxation — strychnine / tetanus: Plumb’s p.598 (Morgan 1988; Schmitz 2004): 110 mg/kg IV. Papich 5e: anaesthetic adjunct 2.2 mL/kg/h of 5% with an alpha-2 agonist and ketamine.
- Expectorant (oral): Papich 5e: dogs and cats 3–5 mg/kg q8h PO as an expectorant.

### Cattle

*Guaifenesin (GGE) doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Induction / TIVA component | 55–110 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- Induction / TIVA component: Plumb’s p.598 (Mandsager 1988): cattle 55–110 mg/kg IV. Use ≤5% to limit haemolysis; titrate. Extra-label — obtain a FARAD withdrawal.

### Horses

*Guaifenesin (GGE) doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Induction muscle relaxation (to effect) | 30–110 mg/kg | IV | to effect | — |
| Triple drip TIVA (with ketamine + xylazine) | 1 L of 5% guaifenesin + 500 mg xylazine + 1–2 g ketamine: 1.1 mL/kg to induce, then 1.5–4 mL/kg/h to effect | IV | CRI to effect | — |

- Induction muscle relaxation (to effect): Papich 5e: 2.2 mL/kg of 5% (110 mg/kg) IV before ketamine; with propofol, 90 mg/kg over 3 min then propofol 3 mg/kg. Plumb’s p.598: label 110 mg/kg IV — give ⅓–½ until the horse relaxes/falls gently, then the rest; after xylazine sedation usually 30–50 mg/kg by rapid pressurised infusion before ketamine 2.2 mg/kg (Abrahamsen 2007); 25–50 mg/kg to deepen a light field anaesthetic. Use ≤5% solutions (haemolysis). ARCI Class 4.
- Triple drip TIVA (with ketamine + xylazine): Papich 5e: 1 L 5% guaifenesin in dextrose + 500 mg xylazine + 2 g ketamine; 1.1 mL/kg for induction then 2–4 mL/kg/h; yohimbine 0.125 mg/kg speeds recovery. Plumb’s p.598 (Wagner 2009): GKX (guaifenesin 50 mg/mL, ketamine 1–2 mg/mL, xylazine 0.5 mg/mL) at 1.5–2.2 mL/kg/h after xylazine/ketamine induction; GKD alternative with detomidine. Calculate the drip rate — do not overdose.

### Goats

*Guaifenesin (GGE) doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Induction / maintenance (as GKX) | 100–110 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- Induction / maintenance (as GKX): Plumb’s p.598: GKX — 1 L of 5% guaifenesin with 1 g ketamine ± up to 100 mg xylazine; induce with 2.2 mL/kg IV (≈110 mg/kg guaifenesin), maintain at about 2.2 mL/kg/h (Wagner 2009); or 500 mL 5% guaifenesin + 50 mg xylazine + 500 mg ketamine at 2–4 mL/kg to recumbency, then slowed (Rings 2005). Calculate carefully — do NOT overdose. Extra-label.

### Sheep

*Guaifenesin (GGE) doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Induction / maintenance (as GKX) | 100–110 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- Induction / maintenance (as GKX): Plumb’s p.598: GKX — 1 L of 5% guaifenesin with 1 g ketamine ± up to 100 mg xylazine; induce with 2.2 mL/kg IV (≈110 mg/kg guaifenesin; calculate — do NOT overdose), maintain at about 2.2 mL/kg/h (Wagner 2009); or 500 mL 5% guaifenesin + 50 mg xylazine + 500 mg ketamine at 2–4 mL/kg IV, fast until recumbent then slowed (Rings 2005). Xylazine can cause hypoxaemia/pulmonary oedema in sheep. Extra-label — obtain a FARAD withdrawal.

### Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

*Guaifenesin (GGE) doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Induction / TIVA component | 55–110 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- Induction / TIVA component: Plumb’s p.598 (Mandsager 1988): cattle 55–110 mg/kg IV. Use ≤5% to limit haemolysis; titrate. Extra-label — obtain a FARAD withdrawal.

### Camelids

*Guaifenesin (GGE) doses for camelids*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Induction / maintenance (as GKX) | 1 L of 5% guaifenesin + 1 g ketamine ± 200 mg xylazine: 2.2 mL/kg IV to induce, then about 2.2 mL/kg/h | IV | CRI to effect | — |

- Induction / maintenance (as GKX): Plumb’s p.598 (Wagner 2009): calculate the dose — do NOT overdose.

## Contraindications

Use as a sole agent (no anaesthesia/analgesia). Perivascular injection (irritant — thrombophlebitis/tissue necrosis). High concentrations >10 % (haemolysis). Hepatic impairment (prolonged effect). Known hypersensitivity. Always secure the airway and support the anaesthetised patient.

## Species-specific warnings

> **Caution:** Cattle: Cattle are more sensitive to guaifenesin — use ≤5 % concentration and lower the dose; titrate to effect.

> **Caution:** Horses: Ensure IV (perivascular injection is severely irritant) and combine with sedation/analgesia for a safe induction and recovery.

## Adverse effects

- Thrombophlebitis / perivascular irritation (especially concentrations >10 %)
- Haemolysis at high concentrations (keep ≤10 %, ideally 5 % in cattle)
- Respiratory depression/apnoea at overdose (relaxes respiratory muscles)
- Hypotension; ataxia/weakness during recovery

## Drug interactions

- Ketamine + alpha-2 agonist (xylazine): the classic synergistic "triple drip" TIVA combination
- Other CNS depressants/anaesthetics: additive depression — reduce co-drug doses
- No significant metabolic interactions of note

## Pregnancy and lactation

Used in pregnant mares/cattle as part of anaesthesia when required; crosses the placenta with other anaesthetics to depress the neonate at caesarean — minimise and resuscitate.

## Monitoring

- Depth of relaxation/anaesthesia (titrate the induction agent after the horse becomes ataxic)
- Respiration (apnoea risk) and oxygenation
- Blood pressure
- IV catheter patency (avoid perivascular injection); recovery quality

## Toxicity and overdose

Overdose causes excessive muscle relaxation with apnoea, hypotension and a prolonged, weak, ataxic recovery. High concentrations cause intravascular haemolysis and, if injected perivascularly, severe tissue irritation and necrosis.

Management: No specific antidote. Support ventilation (the relaxant may compromise breathing), maintain circulation with IV fluids/vasopressors, and provide a calm, assisted recovery. For haemolysis, discontinue and support; for perivascular injection, infiltrate the site and treat as an irritant extravasation.

## Clinical pearls

- Think large-animal field anaesthesia: guaifenesin is the muscle-relaxant backbone of the "triple drip" with ketamine + xylazine
- Never an anaesthetic by itself — it relaxes muscle but does not abolish awareness or pain
- Keep concentration ≤10 % (≤5 % in cattle) to avoid haemolysis, and warm crystallised solution before use
- Strictly intravenous — perivascular leakage causes nasty tissue necrosis
- Titrate to the point of buckling/ataxia, then induce — don't chase deeper relaxation with guaifenesin alone

## Mechanism of action

Centrally acting muscle relaxant that depresses or blocks transmission at internuncial (interneuron) synapses in the spinal cord and brainstem, reducing polysynaptic reflex arcs to produce skeletal-muscle relaxation. It does not act at the neuromuscular junction and has minimal effect on the diaphragm at therapeutic doses; it produces little hypnosis and no analgesia alone.

## Formulations and products

- IV solution 50 mg/mL (5 %)
- IV solution 100 mg/mL (10 %)
- Guaifenesin 5 % IV (compounded/vet) (Various) — 50 mg/mL, IV solution
- Guaifenesin (oral expectorant — different use) — Syrup/tablet (expectorant), Oral expectorant (human-label)

## Storage

Store 15–30 °C; guaifenesin may crystallise/precipitate when cold — warm gently to redissolve before use and check clarity. Protect from freezing.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

## Other sedatives and anaesthetics

- [Detomidine](https://vetmasterji.com/drugs/detomidine)
- [Dexmedetomidine](https://vetmasterji.com/drugs/dexmedetomidine)
- [Diazepam](https://vetmasterji.com/drugs/diazepam)
- [Etomidate](https://vetmasterji.com/drugs/etomidate)
- [Isoflurane](https://vetmasterji.com/drugs/isoflurane)
- [Ketamine HCl](https://vetmasterji.com/drugs/ketamine)
- [Medetomidine](https://vetmasterji.com/drugs/medetomidine)
- [Midazolam](https://vetmasterji.com/drugs/midazolam)

## Frequently asked questions

### What is the dose of Guaifenesin (GGE) for dogs?

Reference doses for Guaifenesin (GGE) in dogs: 110 mg/kg IV repeat as needed (Muscle relaxation — strychnine / tetanus); 3–5 mg/kg PO q8h (Expectorant (oral)). Confirm against the label and the patient before use.

### What is the dose of Guaifenesin (GGE) for cattle?

Reference doses for Guaifenesin (GGE) in cattle: 55–110 mg/kg IV to effect (Induction / TIVA component). Confirm against the label and the patient before use.

### What is the dose of Guaifenesin (GGE) for horses?

Reference doses for Guaifenesin (GGE) in horses: 30–110 mg/kg IV to effect (Induction muscle relaxation (to effect)); 1 L of 5% guaifenesin + 500 mg xylazine + 1–2 g ketamine: 1.1 mL/kg to induce, then 1.5–4 mL/kg/h to effect IV CRI to effect (Triple drip TIVA (with ketamine + xylazine)). Confirm against the label and the patient before use.

### What is the withdrawal period for Guaifenesin (GGE)?

Cattle, IV (Induction / TIVA component): Withdrawal NOT established — treat as extra-label; Goats, IV (Induction / maintenance (as GKX)): Withdrawal NOT established — treat as extra-label; Sheep, IV (Induction / maintenance (as GKX)): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Guaifenesin (GGE) not be used?

Use as a sole agent (no anaesthesia/analgesia). Perivascular injection (irritant — thrombophlebitis/tissue necrosis). High concentrations >10 % (haemolysis). Hepatic impairment (prolonged effect). Known hypersensitivity. Always secure the airway and support the anaesthetised patient.

### What are the side effects of Guaifenesin (GGE) in animals?

Thrombophlebitis / perivascular irritation (especially concentrations >10 %); Haemolysis at high concentrations (keep ≤10 %, ideally 5 % in cattle); Respiratory depression/apnoea at overdose (relaxes respiratory muscles); Hypotension; ataxia/weakness during recovery.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.