Chapter 9 Medical Conditions and Medications That May Impair Driving

This chapter contains a reference list of medical conditions and medications that may impair driving skills, and consensus recommendations for each one. These recommendations apply only to drivers of private motor vehicles and should not be applied to commercial drivers.* Although many of the listed medical conditions are more prevalent in the older population, these recommendations apply to drivers of all ages.

The listed medical conditions were chosen for their relevance to clinical practice. Although the corresponding recommendations are based on scientific evidence whenever possible, please note that use of these recommendations has not been proven to reduce crash risk.** As such, these recommendations are provided to assist physicians in the decision-making process. They are not intended for use as formal practice guidelines, nor as a substitute for the physician’s clinical judgment.

This chapter was adapted from the June 2000 Preliminary Guidelines for Physicians, set forth in Appendix A to Dobbs BM. Medical Conditions and Driving: A Review of the Scientific Literature. Washington, DC: National Highway Traffic Safety Administration; 2003. The review and guidelines were developed by the Association for the Advancement of Automotive Medicine in cooperation with NHTSA.

How to Use This Chapter

Physicians may consult this chapter if they have questions regarding specific medical conditions or medications. If a patient presents with a particular medical condition and related functional deficits (eg, deficits in vision, cognition, or motor function) that may affect his/her driving safety, the physician may base his/her interventions for driving safety on this chapter’s recommendations. Many of the recommendations fall under one or more of the following categories:

• Treat the underlying medical condition to correct functional deficits and prevent further functional decline;
  
• If the functional deficit is due to an offending agent (eg, medication with impairing side effects), remove the offending agent or attenuate its effects, if possible;
  
• Advise the patient on risks to his/her driving safety, and recommend driving restrictions or driving cessation as needed;
  
• If further evaluation is required to determine whether the patient is safe to drive, refer the patient to a driver rehabilitation specialist (DRS) for a driver evaluation (including on-road assessment) whenever possible;
  
• If the patient’s functional deficits are not medically correctable, refer the patient to a DRS whenever possible. The DRS may prescribe adaptive techniques and devices to compensate for these deficits, and train the patient in their use. (See Chapter 5 for further discussion of driver rehabilitation services.)
  

Physicians who receive telephone consults from patients should advise patients against driving—even to seek medical attention—if they report symptoms that are incompatible with safe driving (eg, visual changes, syncope or pre-syncope, vertigo, and severe pain). Such patients should be strongly urged to seek alternative forms of transportation, including cab rides, rides from family and friends, and medical transportation services.

In the inpatient setting, driving should be addressed prior to the patient’s discharge whenever appropriate. Even for the patient whose symptoms clearly preclude driving, it should not be assumed that the patient is aware that he/she should not drive. The physician should counsel the patient regarding driving and discuss a future plan (eg, resumption of driving upon resolution of symptoms, driver rehabilitation upon stabilization of symptoms, permanent driving cessation, etc.).

Medical Conditions and Medications That May Impair Driving

Section 1.....................................Vision

Section 2.....................................Cardiovascular Diseases

Section 3.....................................Cerebrovascular Diseases

Section 4.....................................Neurologic Diseases

Section 5.....................................Medications

Section 6.....................................Psychiatric Diseases

Section 7.....................................Metabolic Diseases

Section 8.....................................Musculoskeletal Disabilities

Section 9.....................................Peripheral Vascular Diseases

Section 10...................................Renal Disease

Section 11...................................Respiratory Diseases

Section 12...................................Effects of Anesthesia and Surgery

Section 13...................................Miscellaneous Conditions

* Commercial drivers have additional responsibilities regarding public safety, and their medical qualification is governed by federal and state regulations.

** Although scientific evidence links certain medical conditions and levels of functional impairment with crash risk, more research is needed to establish that driving restrictions based on these medical conditions and levels of functional impairment significantly reduce crash risk