Yes, Modalert 200 mg Australia can potentially cause an increase in blood pressure, especially in patients with sleep apnea. While it is generally considered safe for promoting wakefulness, Modafinil may lead to mild to moderate increases in blood pressure and heart rate. In individuals with obstructive sleep apnea (OSA), who already have cardiovascular risk factors, the stimulant effect of Modalert could exacerbate hypertension or other heart-related issues. Patients with sleep apnea should consult their healthcare provider before using Modalert to ensure it is safe for their specific condition and to monitor blood pressure regularly during treatment.