Version July 2025
Note: Guanidine has been discontinued in the United States for >1 year.
Eaton-Lambert syndrome: Oral: Initial: 10-15 mg/kg/day in 3-4 divided doses, gradually increase to 35 mg/kg/day, or up to development of side effects.
No dosage adjustment provided in manufacturer’s labeling.
No dosage adjustment provided in manufacturer’s labeling.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Frequency not defined.
Cardiovascular: Atrial fibrillation, cold extremities, flushing, hypotension, palpitations, tachycardia
Central nervous system: Ataxia, confusion, dizziness, emotional lability, hallucination, irritability, jitteriness, mood changes, nervousness, psychosis
Dermatologic: Diaphoresis, folliculitis, paresthesia, skin rash, xeroderma
Gastrointestinal: Abdominal cramps, anorexia, diarrhea, gastric irritation, nausea, sore throat, xerostomia
Genitourinary: Uremia
Hematologic & oncologic: Anemia, bone-marrow depression, bruise, leukopenia, petechia, purpura, thrombocytopenia
Hepatic: Abnormal hepatic function tests
Neuromuscular & skeletal: Tremor
Renal: Increased serum creatinine, interstitial nephritis (acute or chronic), renal tubular necrosis
Miscellaneous: Fever
Hypersensitivity to guanidine or any component of the formulation
Concerns related to adverse effects:
• Bone marrow suppression: Dose-related, fatal bone marrow suppression had been reported with use. Avoid concurrent use with medications known to suppress bone marrow. Monitor closely; discontinue use if bone marrow suppression is suspected.
Disease-related concerns:
• Renal impairment: Use with caution in patients with renal impairment.
Note: Guanidine has been discontinued in the United States for >1 year.
May be product dependent
Tablets (Guanidine HCl Oral)
125 mg (per each): $0.25
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Reduction of the symptoms of muscle weakness associated with the myasthenic syndrome of Eaton-Lambert, not for myasthenia gravis
Guanidine may be confused with guanFACINE
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Acetylcholinesterase Inhibitors: May increase adverse/toxic effects of Cholinergic Agonists. Specifically, cholinergic effects may be enhanced or increased. Risk C: Monitor
Beta-Blockers: May increase adverse/toxic effects of Cholinergic Agonists. Of particular concern are the potential for cardiac conduction abnormalities and bronchoconstriction. Risk C: Monitor
Cimetropium: Cholinergic Agonists may decrease anticholinergic effects of Cimetropium. Risk C: Monitor
Rivastigmine: Cholinergic Agonists may increase adverse/toxic effects of Rivastigmine. Specifically, cholinergic effects may be enhanced or increased. Rivastigmine may increase adverse/toxic effects of Cholinergic Agonists. Management: Use of rivastigmine with a cholinergic agonist is not recommended unless clinically necessary. If the combination is necessary, monitor for increased cholinergic effects. Risk D: Consider Therapy Modification
Sincalide: Drugs that Affect Gallbladder Function may decrease therapeutic effects of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Risk D: Consider Therapy Modification
Animal reproduction studies have not been conducted.
Guanidine is excreted into breast milk. Breastfeeding is not recommended by the manufacturer.
CBC with differential (baseline and frequently thereafter); renal function (creatinine, BUN) and urinalysis (regularly)
