Substance and drug misuse leads to serious health consequences and imposes a significant financial strain on global economies as well as individual households. Nevertheless, there is scarce information regarding socioeconomic inequalities in the consumption of substances of abuse in low- and middle-income nations, including Kenya. This research sought to examine the socioeconomic differences in the patterns of drug and substance use within Murang’a County in central Kenya. A cross-sectional study design was employed, with data gathered from November to December 2017. A sample of 449 households, each having at least one member with a history of substance misuse, was drawn from four deliberately chosen sub-locations in Murang’a County. Heads of households provided responses about housing features and, either personally as users or representing users in their homes. Standardized questionnaires collected information on the kinds of substances consumed, financial implications, and gender dynamics within households. Socioeconomic status (SES) of households was determined (categorized as low, middle, or high) through principal component analysis (PCA) based on various household assets and attributes. Bivariable logistic regression was applied to evaluate links between SES, gender, and additional variables with the adoption of substances and drugs. People from higher SES groups showed greater odds of smoking cigarettes (OR = 2.13; 95% CI = 1.25–3.61, p = 0.005) or using piped tobacco (OR = 11.37; 95% CI = 2.55–50.8; p = 0.001) compared to those from low SES. Wealthier people had lower odds of consuming legal alcohol (OR = 0.39; 95% CI = 0.21–0.71, p = 0.002) relative to the most impoverished. No SES differences were observed in the misuse of prescription medications. When comparing median expenditures on obtaining substances, affluent individuals allocated considerably less money than the poorest (USD 9.71 versus Ksh 14.56, p = 0.031). Fatalities linked to substance and drug misuse were more probable in middle SES households than in the lowest SES ones (OR = 2.96; 95% CI = 1.03–8.45, p = 0.042). Differences based on socioeconomic factors are evident in patterns of drug and substance misuse. People from lower-income backgrounds face elevated risks of misuse, higher spending, and mortality. Efforts to curb substance and drug abuse should tackle these socioeconomic inequalities by implementing focused interventions aimed at lower-income populations.
