Phoenix Prescription Drugs DUI Defense Lawyer (Medications DUI)

Understanding Arizona’s Two Paths to a Prescription-Drug DUI

Driving under the influence (DUI) in Arizona can be charged when prescription medication impairs driving even if taken lawfully.

Arizona prosecutes prescription drug DUIs under two legal theories in A.R.S. § 28-1381:

1. Impairment DUI — § 28-1381(A)(1) Driving “while impaired to the slightest degree” by any drug. A valid prescription is not a defense here. The State must link the drug to unsafe driving.
2. Per-Se Drug DUI — § 28-1381(A)(3) Driving with any prohibited drug (or its metabolite) in your body. Arizona law allows an affirmative defense if the drug was used as prescribed by a licensed medical practitioner.

Why this matters: The prescription defense only applies to the per-se charge — you still need a separate defense for any impairment allegation.

Important Arizona Appellate Cases

• State ex rel. Montgomery v. Harris (Shilgevorkyan) The Arizona Supreme Court ruled that non-impairing metabolites (like carboxy-THC) cannot support a per-se DUI conviction.
• Dobson v. McClennen Medical marijuana patients are not immune from DUI charges but can raise an affirmative defense if they show the amount in their system was too low to cause impairment.
• State v. Bayardi (Court of Appeals)Clarified that in (A)(3) cases, the prescription defense requires proof the drug was taken as directed; dosage deviation can void the defense.

Hypothetical Scenarios That Show How the Law Works

Scenario 1 – Long-Term Medication, No Unsafe Driving

Maria has taken a low dose of alprazolam for 8 years. She’s stopped for a rolling stop at a sign — no weaving or erratic driving. Blood tests confirm the drug.

• Per-Se Charge: We raise the prescription defense under § 28-1381(D) with pharmacy records.
• Impairment Charge: We argue no causal link between the medication and driving — pointing to the stop-sign violation as unrelated.

Scenario 2 – New Prescription, Observable Impairment

Kevin just had dental surgery and takes his first dose of hydrocodone before driving to the pharmacy. He’s seen swerving and braking late.

• Per-Se Charge: Defense may apply if medication was taken as prescribed.
• Impairment Charge: The State will argue Kevin was impaired to the slightest degree; we counter with timing, dosage, and possible alternate explanations (e.g., sudden stops ahead).

Inside Knowledge of Maricopa County DUI Court

• Parallel Charging: Prosecutors often file both (A)(1) and (A)(3) charges, making it essential to attack each separately.
• DRE Evidence: Drug Recognition Expert testimony is common, but judges here often expect strong corroboration (video, FST results) before crediting it heavily.
• MVD & Admin Per Se: A refusal after arrest triggers a 12-month suspension (24 months for prior refusals). Prosecutors know most officers obtain e-warrants for blood draws — we prepare for both criminal and MVD hearings.

Proven Defense Tactics We Use for Prescription-Drug DUI

1. Prescription Documentation Defense
   • Collect pharmacy logs, prescriber letters, and refill history to assert the (A)(3) prescription defense.
2. Challenge Impairment Evidence
   • Question field sobriety tests (often designed for alcohol impairment), show alternative causes for driving issues, and highlight clean body-cam behavior.
3. Toxicology and Chain of Custody Review
   • Check lab calibration, sample handling, and timing between driving and testing to expose unreliable results.
4. Tolerance Argument
   • Show long-term therapeutic use with no impairment — supported by medical testimony.
5. Causation Attack
   • Even if the drug is present, we challenge whether it caused the alleged unsafe driving.

Common Prescription Drugs in Arizona DUI Cases

• Opioids (oxycodone, hydrocodone)
• Benzodiazepines (alprazolam, diazepam)
• Sleep aids (zolpidem)
• Muscle relaxants (carisoprodol)
• Strong antihistamines (diphenhydramine)

What To Do If Charged with a Prescription-Drug DUI

• Do not assume a valid prescription clears you.
• Save all prescription and dosing records.
• Contact a lawyer early — before making statements to law enforcement.

Arizona Justice Law Group — Founding Partner: Zalman Sapad

📍 Phoenix, Arizona • 📞 (602) 730-1756

Your case demands careful legal strategy — we’re here to build it with you.

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