Remifentanil¶
Overview¶
| Field | Detail |
|---|---|
| Drug class | Ultra-short-acting synthetic opioid analgesic |
| Stock vial | 1 mg powder for injection |
| Reconstituted conc. | 0.05 mg/mL (add 20 mL WFI) |
| Storage | Room temp before; 2–8°C after |
Preparation¶
Before you start
Ensure the vial contains 1 mg of Remifentanil. Check expiry and integrity. Note that Remifentanil is a Schedule 8 (S8) medication and requires appropriate handling and witnessing. This requires 20 mL of diluent for the standard 0.05 mg/mL concentration.
Equipment needed¶
- 1 × Remifentanil 1 mg vial
- Water for injection (WFI) — at least 20 mL
- Normal saline (NS) — for IDT dilutions
- 20 mL syringe (for reconstitution)
- 1 mL syringes × 3 (for test doses)
- 25 G needles
Step 1 — Reconstitution¶
- Reconstitute the 1 mg vial with 20 mL WFI.
- Dissolve completely to obtain Remifentanil 0.05 mg/mL (Neat).
Step 2 — Prepare the SPT solution (0.05 mg/mL — neat)¶
- Draw up 0.5–1 mL of the neat (0.05 mg/mL) solution into a 1 mL syringe.
- Label: "Remifentanil SPT 0.05 mg/mL".
Step 3 — Prepare IDT dilutions¶
Prepare in this order, using a fresh syringe for each step.
-
IDT 0.005 mg/mL (1:10):
- Draw 0.1 mL of neat (0.05 mg/mL) into a 1 mL syringe. Add 0.9 mL NS. Mix. (This is 0.005 mg/mL — 1:10).
- Label: "Remifentanil IDT 0.005 mg/mL".
-
IDT 0.0005 mg/mL (1:100):
- Draw 0.1 mL of the 0.005 mg/mL syringe into a new 1 mL syringe. Add 0.9 mL NS. Mix. (This is 0.0005 mg/mL — 1:100).
- Label: "Remifentanil IDT 0.0005 mg/mL".
Skin prick test (SPT)¶
| Reagent | Concentration |
|---|---|
| Test solution | Neat (0.05 mg/mL) |
| Positive control | Histamine 10 mg/mL |
| Negative control | Normal saline |
Interpretation: Wheal ≥3 mm vs negative control = positive.
Intradermal test (IDT)¶
Dilution series¶
| Step | Dilution | Concentration | Preparation |
|---|---|---|---|
| 1 | 1:100 | 0.0005 mg/mL | 0.1 mL of 0.005 mg/mL + 0.9 mL NS |
| 2 | 1:10 | 0.005 mg/mL | 0.1 mL neat + 0.9 mL NS |
Inject: 0.05 mL intradermal. Read at 15–20 minutes.