Medical students knowledge of medicinal drugs and

impairment

E velyn V in gilis, Ph.D

P opulation and C om m unity H ealth U nit, Faculty o f M edicine, T he U niversity o f W estern

O ntario , L ondon, C anada

In recent years a grow ing body o f ev idence has been identify ing the im pairm ent p roperties o f

m any m edicinal d rugs (A soh et al., 1995; B erghaus and G uo, 1995; Del R io and A lvarez,

1995; F reem an and O ’H anlon, 1995; G engo and M anning, 1990; M oskow itz and B urns,

1988; O 'H an lo n and Freem an, 1995). In addition, epidem iological studies have identified

m edicinal d rugs am ong crashed and D U I drivers. F or exam ple, S todu to e t al. (1993) found

that o f their sam ple o f consecutively adm itted m otor vehicle crashed drivers to a m ajor

traum a cen tre in C anada, 12.4% tested positive fo r benzodiazepine , 5% fo r m orphine , 3.8%

for codeine, about 3% each fo r barb itu rates and peth id ine, and about 2% each for

d iphenhydram ine and pheniram ine. O thers have sim ilarly found the presence o f m edicinal

d rugs am ong crashed drivers (C hristophersen et al., 1995; Farriery et al., 1989; Jeffery et al.,

1995). Indeed, D e G ier (1993) has estim ated that at least 10% o f all peop le in ju red o r killed

in road crashes w ere taking som e sort o f psychotropic m edication that m ay have been a

con tribu to ry factor.

U nlike alcohol o r illicit drugs, m edicinal d rugs are subjected to tight contro ls. P harm acies and

physic ians are the prim ary public gatekeepers o f m edicinal drugs. O nly recen tly have

a ttem pts been m ade to educate the m edical p rofession on the poten tial risks o f patien ts

causing traffic crashes under the influence o f prescribed m edicinal d rugs (D el R io and

A lvarez, 1995; O 'H an lo n , 1995a) because the current perception is that physic ians have

lim ited know ledge o f the im pairing properties o f various m edicines. U nfortunately , little

specific in form ation on their know ledge levels is available.

T he purpose o f th is study w as to assess the level o f know ledge on alcoho l and drug

im pairm ent, and the relative im pairm ent properties o f various com m on m edicinal d rugs

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am ong fourth year m edical students in one o f C an ad a’s 16 m edical schools.

M E T H O D

E ighty studen ts in their last sem ester o f m edical school com pleted the su rvey at the beg inn ing

o f their Population H ealth class. T h is represented 84% o f the m edical studen ts en ro lled in the

program m e. S ix ty-one percen t o f the students w ere m ale and 39% w ere fem ale. A t th is poin t

in their education they w ould have com pleted their all their basic and clin ical tra in ing ,

includ ing tra in ing in pharm acology.

T he survey consisted o f 10 m ultip le-cho ice questions, query ing studen ts on their know ledge

o f prevalence o f alcohol and m edicinal drug use am ong in ju red m oto r veh icle crashed drivers,

the m ain classes o f d rugs considered to im pair driv ing perfo rm ance and the re la tive degrees

o f im pairm en t o f a range o f psychotropic drugs.

R E SU L T S

T he average correc t score out o f 10 w as 4, w ith the range from 1 to 8 . H a lf o f the studen ts

scored 3 o r 4 out o f 10. O nly, 12.5% o f the m edical studen ts ac tually scored above 50% .

Specifica lly

T he students generally underestim ated the p revalence o f alcohol and drugs am ong traum a

victim s. A lm ost 46% correctly identified that 60% o f seriously in ju red m otor veh icle crashed

drivers w ere positive fo r alcohol and/or o ther drugs on adm ission to a m ajo r O ntario traum a

unit. H ow ever, 24% correctly identified that 35% o f d rivers w ere positive fo r a lcohol, and

only 2 .5% felt that 40% o f crashed drivers w ere positive for d rugs (lic it and illicit). A lm ost

h a lf o f the students felt tha t only 1 0 % o f the crashed drivers w ere positive fo r any drugs.

Three quarters o f the students d id correctly identify cannabis and benzodiazep ine as the tw o

drugs o th er than alcohol m ost com m only found am ong in ju red drivers.

A ntid iabetic , card iac, ophthalm ological and an tidepressants are all c lasses o f d rugs considered

to im pair d riv ing perform ance. S lightly over three fifths correctly iden tified all the classes as

poten tially im pairing w hile ano ther one fifth sta ted only antidepressants cou ld im pair driv ing

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performance.

Studen ts w ere also asked about the relative risk o f drivers being invo lved in an in ju ry-

p roducing crash after 2 w k. usage o f benzodiazep ine hypnotic com pared to contro ls. C lose to

18% co rrec tly endorsed the 650% greater risk answ er, w hile alm ost th ree quarters felt the risk

to be 2 0 0 % higher.

F inally the studen ts w ere asked to identify am ong various d rugs and dosages the m ost and

least im pairing drugs. T he drugs w ere diazepam (5m g 3/d fo r a w k), lo razepam (2m g 2/d for

a w k), busp irone (lO m g/d for a w k), B A C .08% and 2 jo in ts o f cannabis/dy . A lm ost 40% o f

students iden tified d iazepam as m ost im pairing , ano ther 38% o f studen ts iden tified alcohol at

B A C o f .08% as m ost im pairing , w hile und er 18% correctly endorsed lo razepam as m ost

im pairing . A lm ost 37% o f the students correctly chose d iazepam as the second m ost

im pairing d rug , a lthough 27% did choose B A C o f .08% .

T he m ajority o f studen ts (62% ) d id correctly chose busp irone as the least im pairing drug,

a lthough alm ost 1 0 % o f the students d id say that lo razepam w as the least im pairing .

Finally , the studen ts w ere asked, w hich o f the fo llow ing drugs, flouxetine , fluvoxam in,

nom ifensine, am itrip ty line and paroxetine, causes the m ost im pairm ent. Seventy tw o percen t

correc tly answ ered am itrip ty line.

D ISC U S SIO N

T hese find ings suggest that at the end o f form al m edical school, m edical students have

lim ited know ledge o f the im pairing properties o f m edicinal drugs. Indeed , one m edical

student w rote on the top o f his questionnaire , «I d o n ’t th ink w e w ere ever taught this in our

four years here. I t 's a sham e». I th ink that sta tem ent says it all. E xcep t fo r the questions on

the im pairm ent levels o f busp irone and am itrip ty line, w here the m ajority o f students scored

co rrec tly , the o th er questions w ere scored at chance levels. P articu la rly o f concern shou ld be

the fact that alm ost 1 0 % o f these fourth year m edical students felt that lo razepam w as the

L E A S T im pairing drug. O ’H anlon (1995b) has stated that « lo razepam should p robab ly never

be p rescribed to patien ts w ho drive, o r at least they should be p roh ib ited from d riv ing for

several w eeks after sta rting m edication , because ...even the low est therapeu tic dose 0 .5 m g,

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three times a day, had more effect on driving performance than BAC=.05%».

In addition , the m edical students clearly underestim ated the ex ten t o f drug use am ong

hosp italized crashed drivers. Y et in O ntario, the m edical p rofession has cause fo r concern.

R ecently , physic ians have been found partly liable fo r car crash aw ards fo r failing to repo rt to

the M in istry o f T ransportation , a legal requirem ent in O ntario , that drivers had conditions that

cou ld affect their driv ing (O nyshko, 1994; O w ens 1993). Furtherm ore, physic ians have been

disc ip lined by the O ntario C ollege o f Physicians and Surgeons (1993) fo r im proper

prescrib ing w hich led to veh icular crashes. F inally , the issue regard ing m edical

conditions/p rob lem s, crash risk and duty to inform the M inistry o f T ransportation has been

described in the C anadian M edical A ssociation Journal (Johnson, 1993). O n an added note,

the H ippocratic O ath requires the physician to «do no harm ». In light o f the fact that our

populations in the industria lized w orld are aging, are m ore p rone to use m any m edicinal

drugs and to have poorer driv ing skills and records, and that trends tow ard de­

institu tionalization and post-operative short hospital days o f stay are increasing , the tim e has

com e to transfer the know ledge gleaned from decades o f research by IC A D T S researchers on

the im pairing p roperties o f m edicinal drugs to the m edical schools and m edical profession .

R E F E R E N C E S

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M etaanalysis o f E xperim ental S tudies as B asic Inform ation to patients, P hysicians and

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N orw egian drivers in road traffic accidents. In: P roceedings o f the 13m International

C onference on A lcohol. D rugs and T raffic S afety . C N K loeden and AJ M cLean (Eds), 768-

779.

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C ollege o f Physicians and Surgeons o f O ntario . (1993). M ediating com plain ts 2: Im proper

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D el R io, M .C . & A lvarez, F.J. (1995). P rescrib ing m edication fo r the driver: T he ro le o f

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Freem an, H. & O ’H anlon, J.F. (1995). A cute and subacute effects o f antidepressan ts on

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veh icle accidents in B ritish C olum bia, Canada: A one year study. In: P roceed ings o f the 13111

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M oskow itz, H. and B urns, M . (1988). T he effects on perform ance o f tw o antidepressants,

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traffic acciden ts w hile unde the influence o f prescribed psychoactive m edication . P rim ary

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O ’H anlon, J.F . (1995b). M edicinal drugs and driving: a som ber perspective from the resu tls

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T ransporta tion R esearch B oard , W ashington , D C., January 10.

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antidepressants. B ritish Journal o f P sych ia try . 166: 421-423.

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patients and healthy volunteers in a standard ized test. N eu ropsvchob io logv . 31: 81-88.

O nyshko, T. (1994). D ocs w ere negligent fo r failing to repo rt that patien t sh o u ld n ’t driver:

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