Which medication is a concern for clients regarding osteoporosis risk?

Phenytoin is associated with an increased risk of osteoporosis, particularly due to its effects on vitamin D metabolism and calcium absorption. This anticonvulsant medication can lead to decreased bone density over time, making individuals more susceptible to fractures and bone-related issues.

In contrast, the other medications listed do not have such a profound impact on bone health. Ibuprofen, while it is a non-steroidal anti-inflammatory drug, is not directly linked to osteoporosis risk. Metformin is primarily used for managing diabetes and does not adversely affect bone density. Statins are used for lowering cholesterol levels and have not been implicated in increasing osteoporosis risk either. Therefore, phenytoin stands out as the medication of concern regarding osteoporosis risk among the options presented.