Mepivacaine¶

Overview¶

Preparation¶

Equipment needed¶

• 1 × Mepivacaine 30 mg/mL vial
• Water for injection (WFI) — at least 5 mL (for reconstitution)
• Normal saline (NS) — for IDT dilutions
• 10 mL syringe (for initial dilution)
• 1 mL syringes × 5 (for test doses/dilutions)
• 25 G needles

Step 1 — Initial Dilution (to 10 mg/mL Neat)¶

1. Draw up 2.2 mL of stock (30 mg/mL = 66 mg).
2. Add 4.4 mL WFI. Mix.
3. Total volume is 6.6 mL (66 mg / 6.6 mL = 10 mg/mL Neat).

Step 2 — Prepare the SPT solution (10 mg/mL)¶

1. Draw up 0.5–1 mL of the 10 mg/mL solution into a 1 mL syringe.
2. Label: "Mepivacaine SPT 10 mg/mL".

Step 3 — Prepare IDT dilutions¶

Prepare in this order, using a fresh syringe for each step.

1. IDT 0.01 mg/mL (1:1,000):

   • A: Draw 0.1 mL of the 10 mg/mL Neat into a 1 mL syringe. Add 0.9 mL NS. Mix. (This is 1 mg/mL — 1:10).
   • B: Draw 0.1 mL of A (1 mg/mL) into a new 1 mL syringe. Add 0.9 mL NS. Mix. (This is 0.1 mg/mL — 1:100).
   • C: Draw 0.1 mL of B (0.1 mg/mL) into a new 1 mL syringe. Add 0.9 mL NS. Mix. (This is 0.01 mg/mL — 1:1,000).
   • Label: "Mepivacaine IDT 0.01 mg/mL".

2. IDT 0.1 mg/mL (1:100):

   • Draw 0.1 mL of syringe B (0.1 mg/mL) into a new 1 mL syringe.
   • Label: "Mepivacaine IDT 0.1 mg/mL".

3. IDT 1 mg/mL (1:10):

   • Draw 0.1 mL of syringe A (1 mg/mL) into a new 1 mL syringe.
   • Label: "Mepivacaine IDT 1 mg/mL".

4. IDT 10 mg/mL (Neat):

   • Draw up a fresh 0.5 mL of 10 mg/mL Neat.
   • Label: "Mepivacaine IDT 10 mg/mL — Neat".

Skin prick test (SPT)¶

Interpretation: Wheal ≥3 mm vs negative control = positive.

Intradermal test (IDT)¶

Dilution series¶

Inject: 0.05 mL intradermal. Read at 15–20 minutes.