Dosage and Administration
Administration
Administer hyoscyamine orally.
Administer hyoscyamine sulfate orally, sublingually, or by sub-Q, IM, or IV injection.
Oral Administration
Immediate-release Preparations
Conventional tablets, elixir, oral solution (drops), orally disintegrating tablets, and sublingual tablets generally administered orally 3–6 times daily. One manufacturer (Symax® FasTab®, Symax® SL) recommends administration 30–60 minutes before meals.
Place orally disintegrating tablet on the tongue, allow it to disintegrate, then swallow with or without water.
Certain sublingual tablets (Levsin®/SL, certain generic preparations) may be chewed.
Oral administration of sublingual tablets results in similar pharmacologic effects as sublingual administration, but onset may not be as rapid.
Extended-release Preparations
Do not crush or chew extended-release preparations.
Administer Levbid® extended-release tablets (or generic preparations) orally every 12 hours; tablets are scored and may be broken to titrate dosage.
Administer extended-release capsules (Levsinex® Timecaps®, generic preparations), Symax® SR extended-release tablets, and Symax® DuoTab® bilayer extended-release tablets orally every 12 hours; swallow capsules or tablets whole; may adjust dosage by reducing dosing interval to 8 hours. One manufacturer (Symax® DuoTab®, Symax® SR) recommends administration 30–60 minutes before meals.
Sublingual Administration
Sublingual tablets generally administered 3–6 times daily. One manufacturer (Symax® SL) recommends administration 30–60 minutes before meals and at bedtime.
Parenteral Administration
Administer by sub-Q, IM, or IV injection without prior dilution.
Dosage
Available as hyoscyamine and hyoscyamine sulfate; dosage of hyoscyamine sulfate expressed in terms of the salt.
Titrate dosage carefully according to the condition, severity of symptoms, and the individual patient’s response and tolerance to the drug. Higher than recommended dosage may be required for therapeutic effect. Use lowest possible effective dosage.
Pediatric Patients
General Hyoscyamine Sulfate Dosage (for GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity)
See GU Disorders dosage section for hyoscyamine dosage for GU disorders.
Oral
Recommended dosages of hyoscyamine sulfate vary by age and/or formulation (see Tables 1–4).
Table 1. Usual Dosages of Hyoscyamine Sulfate (as Oral Solution [Drops]) for Management of GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity in Pediatric Patients <2 Years of Age
| Body Weight |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| 3.4 kg (7.5 lb) |
4 drops (15.63 mcg) every 4 hours or as needed |
24 drops (93.75 mcg) |
| 5 kg (11 lb) |
5 drops (19.53 mcg) every 4 hours or as needed |
30 drops (117.19 mcg) |
| 7 kg (15 lb) |
6 drops (23.44 mcg) every 4 hours or as needed |
36 drops (140.63 mcg) |
| 10 kg (22 lb) |
8 drops (31.25 mcg) every 4 hours or as needed |
48 drops (187.5 mcg) |
| Using the dropper provided by the manufacturer, which is calibrated to deliver approximately 32 drops/mL. |
Table 2. Usual Dosages of Hyoscyamine Sulfate for Management of GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity in Children 2–11 Years of Age
| Formulation(s) |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| Conventional tablets, orally disintegrating tablets, or sublingual tablets |
62.5–125 mcg every 4 hours or as needed
Symax® SL: 62.5–125 mcg 3 or 4 times daily given 30–60 minutes before meals and at bedtime |
750 mcg |
| Elixir |
Weight-based dosing (see Table 3) |
|
| Oral solution (drops) |
31.25–125 mcg every 4 hours or as needed |
750 mcg |
| Bilayer extended-release tablets, extended-release capsules, extended-release tablets |
375 mcg every 12 hours |
750 mcg |
Table 3. Weight-based Dosing of Hyoscyamine Sulfate (as Elixir) for Management of GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity in Children 2–11 Years of Age
| Body Weight |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| 10 kg (22 lb) |
1.25 mL (31.25 mcg) every 4 hours or as needed |
7.5 mL (187.5 mcg) |
| 20 kg (44 lb) |
2.5 mL (62.5 mcg) every 4 hours or as needed |
15 mL (375 mcg) |
| 40 kg (88 lb) |
3.75 mL (93.75 mcg) every 4 hours or as needed |
22.5 mL (562.5 mcg) |
| 50 kg (110 lb) |
5 mL (125 mcg) every 4 hours or as needed |
30 mL (750 mcg) |
Table 4. Usual Dosages of Hyoscyamine Sulfate for Management of GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity in Children ≥12 Years of Age
| Formulation(s) |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| Conventional tablets, elixir, oral solution (drops), orally disintegrating tablets, sublingual tablets |
0.125–0.25 mg every 4 hours or as needed
Symax® SL tablets: 0.125–0.25 mg 3 or 4 times daily given 30–60 minutes before meals and at bedtime |
1.5 mg |
| Bilayer extended-release tablets, extended-release capsules, extended-release tablets |
0.375–0.75 mg every 12 hours. Alternatively, may adjust dosage to 0.375 mg every 8 hours as needed |
1.5 mg |
Sublingual
Children 2–11 years of age: 62.5–125 mcg (0.0625–0.125 mg) hyoscyamine sulfate every 4 hours or as needed, not to exceed 750 mcg in a 24-hour period. For Symax® SL tablets, 62.5–125 mcg 3 or 4 times daily given 30–60 minutes before meals and at bedtime.
Children ≥12 years of age: 0.125–0.25 mg hyoscyamine sulfate every 4 hours or as needed, not to exceed 1.5 mg in a 24-hour period. For Symax® SL tablets, 0.125–0.25 mg 3 or 4 times daily given 30–60 minutes before meals and at bedtime.
GU Disorders
Oral
Hyoscyamine: In older pediatric patients, reduce dosage (compared with adult dosage) in proportion to age and weight. (See Adults under Dosage and Administration.)
Hyoscyamine sulfate: See General Hyoscyamine Sulfate Dosage section.
Sublingual
See General Hyoscyamine Sulfate Dosage section.
Infant Colic
Oral
Children <2 years of age: Dosage of hyoscyamine sulfate based on weight (see Table 5).
Table 5. Usual Dosages of Hyoscyamine Sulfate (as Oral Solution [Drops]) for Management of Infant Colic in Pediatric Patients <2 Years of Age
| Body Weight |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| 3.4 kg (7.5 lb) |
4 drops (15.63 mcg) every 4 hours or as needed |
24 drops (93.75 mcg) |
| 5 kg (11 lb) |
5 drops (19.53 mcg) every 4 hours or as needed |
30 drops (117.19 mcg) |
| 7 kg (15 lb) |
6 drops (23.44 mcg) every 4 hours or as needed |
36 drops (140.63 mcg) |
| 10 kg (22 lb) |
8 drops (31.25 mcg) every 4 hours or as needed |
48 drops (187.5 mcg) |
| Using the dropper provided by the manufacturer, which is calibrated to deliver approximately 32 drops/mL. |
Surgery
Preoperatively to Decrease Secretions and Block Cardiac Vagal Reflexes
IV, IM, or Sub-Q
Children >2 years of age: 5 mcg/kg (0.005 mg/kg) hyoscyamine sulfate given 30–60 minutes before anesthesia or concurrently with other preanesthetic medications (e.g., opiates, sedatives).
Reversal of Drug-induced Bradycardia
IV
Children >2 years of age: 0.125 mg hyoscyamine sulfate; repeat as necessary.
Muscarinic Blockade during Anticholinesterase Reversal of Curariform Neuromuscular Blockade
IV
Children >2 years of age: 0.2 mg hyoscyamine sulfate for each 1 mg of neostigmine methylsulfate or the equivalent dose of physostigmine salicylate or pyridostigmine bromide administered.
Administer concurrently with (but in a separate syringe) or a few minutes before the anticholinesterase agent.
If bradycardia is present, administer before the anticholinesterase agent to increase pulse to about 80 bpm.
Adults
General Hyoscyamine Sulfate Dosage (for GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity)
See GI Disorders dosage section for parenteral hyoscyamine sulfate dosage for GI disorders and see GU Disorders dosage section for hyoscyamine dosage for GU disorders.
Oral
Recommended dosages of hyoscyamine sulfate vary by formulation (see Table 6).
Table 6. Usual Dosages of Hyoscyamine Sulfate for Management of GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity in Adults
| Formulation(s) |
Usual Dosage |
Maximum Dosage in a 24-hour Period |
| Conventional tablets, elixir, oral solution (drops), orally disintegrating tablets, sublingual tablets |
0.125–0.25 mg every 4 hours or as needed
Symax® SL tablets: 0.125–0.25 mg 3 or 4 times daily given 30–60 minutes before meals and at bedtime |
1.5 mg |
| Bilayer extended-release tablets, extended-release capsules, extended-release tablets |
0.375–0.75 mg every 12 hours. Alternatively, may adjust dosage to 0.375 mg every 8 hours as needed |
1.5 mg |
Sublingual
0.125–0.25 mg hyoscyamine sulfate every 4 hours or as needed, not to exceed 1.5 mg in a 24-hour period.
Symax® SL tablets: 0.125–0.25 mg hyoscyamine sulfate 3 or 4 times daily given 30–60 minutes before meals and at bedtime.
GI Disorders
Oral
See General Hyoscyamine Sulfate Dosage section.
Sublingual
See General Hyoscyamine Sulfate Dosage section.
IV, IM, or Sub-Q
0.25–0.5 mg hyoscyamine sulfate every 4 hours, 2–4 times daily; for acute symptoms, a single parenteral dose of 0.25–0.5 mg may be sufficient. Adjust dosage according to individual patient’s response and tolerance.
GU Disorders
Oral
Hyoscyamine: 0.15–0.3 mg up to 4 times daily.
Hyoscyamine sulfate: See General Hyoscyamine Sulfate Dosage section.
Sublingual
See General Hyoscyamine Sulfate Dosage section.
Surgery
Preoperatively to Decrease Secretions and Block Cardiac Vagal Reflexes
IV, IM, or Sub-Q
5 mcg/kg (0.005 mg/kg) hyoscyamine sulfate given 30–60 minutes before anesthesia or concurrently with other preanesthetic medications (e.g., opiates, sedatives).
Reversal of Drug-induced Bradycardia
IV
0.125 mg hyoscyamine sulfate; repeat as necessary.
Muscarinic Blockade during Anticholinesterase Reversal of Curariform Neuromuscular Blockade
IV
0.2 mg hyoscyamine sulfate for each 1 mg of neostigmine methylsulfate or the equivalent dose of physostigmine salicylate or pyridostigmine bromide administered.
Administer concurrently with (but in a separate syringe) or a few minutes before the anticholinesterase agent.
If bradycardia is present, administer before the anticholinesterase agent to increase pulse to about 80 bpm.
Pesticide Poisoning
Organophosphate Anticholinesterase Pesticides
Initial dose preferably should be administered IV.
A cholinesterase reactivator (pralidoxime) is administered concomitantly.
IV or IM, then Oral
Initially, 1–2 mg hyoscyamine sulfate IV. May administer additional 1-mg doses IV or IM every 3–10 minutes until muscarinic signs and symptoms disappear; up to 25 mg may be required during first 24 hours. Subsequently, administer 0.5–1 mg hyoscyamine sulfate orally at intervals of several hours (maintenance therapy) until signs and symptoms completely subside.
Radiographic Uses
Endoscopy or Hypotonic Duodenography
IV, IM, or Sub-Q
0.25–0.5 mg hyoscyamine sulfate 5–10 minutes prior to the diagnostic procedure.
Prescribing Limits
Pediatric Patients
GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity
Oral or Sublingual
Pediatric patients <2 years of age receiving hyoscyamine sulfate oral solution (drops): In a 24-hour period, maximum 24 drops (93.75 mcg) in infants weighing 3.4 kg, 30 drops (117.19 mcg) in infants weighing 5 kg, 36 drops (140.63 mcg) in infants weighing 7 kg, or 48 drops (187.5 mcg) in infants weighing 10 kg.
Children 2–11 years of age: Maximum 750 mcg hyoscyamine sulfate in a 24-hour period. For weight-based dosing using elixir, in a 24-hour period, maximum 7.5 mL (187.5 mcg) in children weighing 10 kg, 15 mL (375 mcg) in children weighing 20 kg, 22.5 mL (562.5 mcg) in children weighing 40 kg, or 30 mL (750 mcg) in children weighing 50 kg.
Children ≥12 years of age: Maximum 1.5 mg hyoscyamine sulfate in a 24-hour period.
Infant Colic
Oral
Pediatric patients <2 years of age receiving hyoscyamine sulfate oral solution (drops): In a 24-hour period, maximum 24 drops (93.75 mcg) in infants weighing 3.4 kg, 30 drops (117.19 mcg) in infants weighing 5 kg, 36 drops (140.63 mcg) in infants weighing 7 kg, or 48 drops (187.5 mcg) in infants weighing 10 kg.
Adults
GI/GU/Biliary Disorders, Renal Colic, Acute Rhinitis, Parkinsonian Syndrome, or Cholinesterase Inhibitor Toxicity
Oral or Sublingual
Maximum 1.5 mg hyoscyamine sulfate in a 24-hour period.
Special Populations
Geriatric Patients
Geriatric patients may be more sensitive to drug’s effects at usual adult dosages.
Select dosage with caution, usually starting at low end of dosing range, because of age-related decreases in hepatic, renal, and/or cardiac function and potential for concomitant disease and drug therapy. (See Geriatric Use under Cautions.)
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