Thiamine Injection - Administration Guide

Indications for Parenteral Thiamine

• Wernicke's encephalopathy (most urgent)
• Alcohol withdrawal / Wernicke-Korsakoff syndrome prevention
• Beriberi (wet or dry)
• Severe malnutrition, refeeding syndrome
• Hyperemesis gravidarum (pregnancy vomiting)
• Any patient receiving IV glucose who may be thiamine-deficient

Routes of Administration

Doses by Indication

• Standard: 100 mg IV initial dose, then 50-100 mg IM/IV daily until regular diet resumed
• High-dose (RCP/European guideline): 500 mg IV three times daily x 3 days, then if responding: 250 mg IM/IV once daily x 5 days

• Dry (peripheral neuropathy): 10-25 mg/day IM or slow IV x 2 weeks
• Wet (cardiac failure): Must give IV slowly - treat as emergency; 100-500 mg IV may be needed

• 100 mg IM or IV, then 100 mg orally/IM/IV for up to 5 days

• 5-10 mg IM daily

Step-by-Step: IV Injection

1. Check the solution - should be clear and colourless; discard if cloudy or contains particles
2. Dilute for infusion: Mix in 50-100 mL normal saline (0.9% NaCl)
3. Rate: Infuse over at least 30 minutes (minimum 10 minutes for slow direct IV push)
4. Never give as rapid IV bolus - risk of anaphylaxis and cardiovascular collapse
5. Have resuscitation equipment ready (anaphylaxis can occur with any parenteral dose)
6. Give before glucose - always administer thiamine BEFORE any dextrose/glucose infusion in at-risk patients; glucose loading can precipitate or worsen Wernicke's by consuming the last thiamine reserves

Step-by-Step: IM Injection

1. Site: Deltoid or gluteal (vastus lateralis in infants)
2. Draw up the required dose; inspect solution
3. Clean skin with alcohol swab; allow to dry
4. Insert needle at 90 degrees; aspirate to confirm not in vessel
5. Inject slowly; withdraw needle; apply light pressure
6. Single-use only - discard any remaining solution after use
7. Monitor for local reaction

Critical Safety Points

• Anaphylaxis risk: Parenteral thiamine can rarely cause anaphylactic reactions. Always have adrenaline (epinephrine), antihistamines, and resuscitation equipment available before giving any injection.
• Skin test: If the patient has a history of allergic reaction to a previous thiamine injection, give a diluted intradermal test dose first.
• Glucose before thiamine = dangerous: In any thiamine-deficient patient (alcoholic, malnourished), giving IV glucose FIRST can precipitate acute Wernicke's encephalopathy. Thiamine always comes first.
• IM preferred over IV when urgency allows - lower anaphylaxis risk than rapid IV
• Repeated IM injections: Can cause local reactions; rotate sites
• Oral route is equally effective as parenteral for non-acute alcoholics after 5 days of parenteral loading

Available Formulations

• 100 mg/mL solution (most common - 1 mL or 2 mL vials)
• 50 mg/mL solution

Calcium Gluconate Injection - Administration Guide

Key Facts First

• Route: IV only - NEVER give IM or SC (causes severe local necrosis and abscess formation)
• Formulation: 10% solution = 100 mg/mL (1 g per 10 mL ampule)
• Elemental calcium content: Each 1 g (10 mL of 10%) contains ~93 mg elemental calcium (less than calcium chloride)

Indications

• Acute symptomatic hypocalcemia (tetany, seizures, laryngospasm)
• Hyperkalemia (cardiac membrane stabilization)
• Hypermagnesemia
• Calcium channel blocker toxicity / overdose
• HF fluoride poisoning
• Patients receiving dextrose who are at risk of hypocalcemia

Doses by Indication

Step-by-Step: Bolus IV Administration

1. Check the solution - must be clear; discard if turbid or has precipitate
2. Warm to body temperature - cold solution increases risk of venous irritation
3. Choose the access site:
   • Prefer central venous line (CVC) when possible - less risk of extravasation injury
   • If peripheral IV used: choose a large, well-functioning vein; avoid hand/foot veins
   • Do NOT use scalp veins in neonates
4. Dilute (recommended): Mix 10-20 mL of 10% solution in 50-100 mL of normal saline (0.9% NaCl) or 5% dextrose
5. Attach cardiac monitor (ECG) - mandatory for bolus administration
6. Infuse slowly:
   • Adults: no faster than 200 mg/min (i.e., 10 mL of 10% solution over at least 5 minutes; ideally over 10 minutes)
   • Children: no faster than 100 mg/min
7. Monitor the patient throughout for bradycardia, hypotension, flushing, or arrhythmia
8. Check serum calcium every 4-6 hours during intermittent infusions; every 1-4 hours during continuous infusion

Step-by-Step: Continuous IV Infusion

1. Dilute in 250-500 mL of NS or D5W
2. Start at the low end of the recommended rate (5.4 mg/kg/hour in adults)
3. Adjust rate based on repeat serum calcium levels
4. Reassess every 1-4 hours

Critical Safety Points

Calcium Gluconate vs Calcium Chloride

Common Side Effects

• Flushing and warmth sensation during injection (normal at slow rates)
• Nausea, vomiting, metallic/chalky taste
• Bradycardia (if given too fast)
• Local venous irritation