OBJECTIVES: Recent studies have reported that a very high number of hypertensive patients’ discontinue their treatment which may be attributed to issues such as unattained blood pressure goals, adverse drug events, drug cost, or personal factors. Treatment modifications (TMs) – addition, uptitration, switching, and downtitration – are necessary to address these issues. This study assessed patterns of TMs across the antihypertensive drug classes (ADCs) used as first-line treatment. We compared the rates of TM and time-to-TM across ADCs. Additionally, we determined the association between TM strategies and the likelihood of treatment discontinuation. METHODS: This is a retrospective cohort study using the BlueCross-BlueShield of Texas commercial claims database (2008-2012). We identified TMs that occurred within one year of starting hypertension treatment. Patients who received a TM were followed for 12 months to determine if and when they discontinued treatment. Cox regression models were used to identify the likelihood of TM, time-to-TM, and the likelihood of treatment discontinuation.   RESULTS: About 48.5% patients received at least one TM within one year of treatment initiation. The rates of TM were significantly different across ADCs; angiotensin converting enzyme inhibitor and angiotensin receptor blocker users were less likely to receive TMs compared to other drug classes. The mean time-to-TM was >100 days for patients adding or uptitrating medications, and >150 days for those switching or downtitrating medications. The likelihood of discontinuation was significantly lower for patients intensifying treatment by adding medications vs. those uptitrating dose (HR=0.765; CI: 0.701-0.834). CONCLUSIONS: TMs are common among newly treated hypertensive patients. The rates of TM vary significantly across ADCs. In the real-world, TMs occur much later than the 30-day time-line recommended by clinical guidelines. Addition of drugs may be a preferred approach vs. uptitrating drug dose for intensifying treatment of patients who are at a high risk of treatment discontinuation.