Evaluation of Knowledge of Food–Drug and Alcohol–Drug Interactions Among Undergraduate Students at King Saud University – An Observational Study

Figures & data

Table 1 Demographic Characteristics and Basic Information of the Study Sample

Characteristics	Frequency (n)	Percentage (%)
Age
18–25	133	93.7
26–30	09	6.3
Level of education
Third-year	70	49.3
Fourth-year	72	50.7
Nationality
Saudi	135	95.1
Non-Saudi	7	4.9
Do you think you have enough information about FDIs and ADIs?
Yes	50	35.2
No	54	38
I Do not know	38	26.7
Which of the following age groups is most susceptible to FDIs?
Children	31	21.8
Adults	7	4.9
Elderly	86	60.6
I do not know	18	12.7

Figure 1 Source of knowledge of FDIs and ADIs.

Table 2 Participants’ Knowledge About Food–Drugs Interactions

Food–Drugs Interactions Questionnaire	Correct Answer (n) (%)
Can amiodarone be taken with grapefruit?	61(43%)
Can atorvastatin be taken with grapefruit?	62(43.7%)
Does cauliflower consumption affect the efficacy of levothyroxine?	23(16.2%)
Does caffeine consumption affect the efficacy of diazepam?	61(43%)
Patients can eat more green leafy vegetables with Coumadin	58(40.8%)
Patients taking theophylline should avoid excessive coffee and tea?	12(8.5%)
Does milk affect the efficacy of tetracycline?	75(52.8%)
Patients taking monoamine oxidase inhibitors (MAOIs) should avoid eating aged cheeses?	67(47.2%)
Does the wheat bran diet affect the efficacy of digoxin?	17(12%)
Do protein-rich foods affect the efficacy of levodopa?	17(12%)
Grapefruit juice can be safely consumed with all antibiotics?	61(43%)
Patients should avoid taking spironolactone with food rich in potassium?	16(11.3%)

Figure 2 Knowledge of grapefruit interactions with selected drugs.

Table 3 Participants’ Knowledge About Alcohol–Drugs Interactions (ADIs)

Alcohol–Drugs Interactions Questionnaire	Frequency (n)	Percentage (%)	Correct Answers, (%)
Do antihistamines interact with alcohol?
Yes	75	52.8	75(52.8)
No	9	6.3
I Do not know	58	40.8
Does Paracetamol interact with alcohol?
Yes	72	50.7	72(50.7%)
No	12	8.5
I Do not know	58	40.9
Does Metformin interact with alcohol?
Yes	53	37.3	53(37.3%)
No	14	9.9
I Do not know	75	52.8
Does isoniazid interact with alcohol?
Yes	51	35.9	51(35.9%)
No	8	5.6
I Do not know	83	58.5
Does warfarin interact with alcohol?
Yes	64	45.1	64(45.1%)
No	18	5.6
I Do not know	70	49.3
Does methotrexate interact with alcohol?
Yes	59	41.5	59(41.5%)
No	9	6.3
I Do not know	74	52.1

Table 4 Influence of Respondents’ Characteristics on Their Knowledge Level About Food–Drug Interactions, and Alcohol–Drug Interactions

Participants Characters	Number of Respondents	Food–Drug Interactions			Alcohol–Drug Interactions
		Not Knowledgeable (N=79; 55.6%)	Knowledgeable (N=63; 44.4%)	P value	Not Knowledgeable (N=86; 60.6%)	Knowledgeable (N=56; 39.4%)	p value
Age
18–29 years	Respondents	75	58	0.485	83	50	0.084*
	% within age	56.4%	43.6%		62.4	37.6
	% within knowledge categories	94.9%	92.1%		96.5	89.3
26–30 years	Respondents	04	0.5		03	06
	% within age	44.4%	55.6%		33.3	66.7
	% within knowledge categories	5.1%	7.9%		3.5	10.7
Education
Third-year	Respondents	59	11	0.0001	56	14	0.0001
	% within the level of education	84.3%	15.7%		80.0	20
	% within knowledge categories	74.7%	17.5%		65.1	25
Fourth-year	Respondents	20	52		30	42
	% within the level of education	27.8%	72.2%		41.7	58.3
	% within knowledge categories	25.3%	82.5%		34.9	75.0
Information about DFIs and ADIs ?
Yes	Respondents	18	32	0.0001	21	29	0.0002
	% within information	36.0%	64.0%		42	58
	% within knowledge categories	22.8%	50.8%		24.4	51.8
No	Respondents	40	14		41	13
	% within information	74.1%	25.9%		75.9	24.1
	% within knowledge categories	50.6%	22.2%		47.7	23.2
I do not know	Respondents	21	17		24	14
	% within information	55.3%	44.7%		63.2	36.8
	% within knowledge categories	26.6%	27.0%		27.9	25

Note: *Fisher exact test.

Table 5 Cross-Tabulation Between Demographic Characteristics and Knowledge Categories of Overall DFIs

Participants Characters	Number of Respondents	Not Knowledgeable (N=74; 52.1%)	Knowledgeable (N=68; 47.9%)	P value
Age
18–25 years	Respondents	71	62	0.244*
	% within age	53.4%	46.6%
	% within knowledge categories	95.9%	91.2%
26–30 years	Respondents	03	06
	% within age	33.3%	66.7%
	% within knowledge categories	4.1%	8.8%
Education Level
Third-year	Respondents	56	14	0.0001
	% within education level	80.0%	20.0%
	% within knowledge categories	75.7%	20.6%
Fourth-year	Respondents	18	54
	% within education level	25.0%	75.0%
	% within knowledge categories	24.3%	79.4%
Do you have information about DFIs and ADIs?
Yes	Respondents	14	36	0.0001
	% within having information	28.0%	72.0%
	% within knowledge categories	18.9%	52.9%
No	Respondents	40	14
	% within having information	74.1%	25.9%
	% within knowledge categories	27.0%	20.6%
I do not know	Respondents	20	18
	% within having information	52.6%	47.4%
	% within knowledge categories	27.0%	26.5%

Note: *Fisher exact test.