| Route of Administration | Time Until Drug Takes Effect* |
|---|---|
| Topical | Hours to days |
| Oral | 30–90 min |
| Rectal | 5–30 min (unpredictable) |
| Subcutaneous injection | 15–30 min |
| Intramuscular injection | 10–20 min |
| Sublingual tablet | 3–5 min |
| Inhalation | 3 min |
| Endotracheal | 3 min |
| Intravenous | 30–60 sec |
| Intracardiac | 15 sec |
* In a healthy person with normal perfusion.