Immediate Treatment: Initiate Beta-Blocker and Antithyroid Medication for Hyperthyroidism
You should immediately start propranolol (or another beta-blocker) to control the severe anxiety symptoms and cardiovascular manifestations of hyperthyroidism, while simultaneously initiating methimazole as definitive antithyroid therapy. The patient's anxiety is likely predominantly driven by untreated hyperthyroidism (TSH 0.06, elevated TPO antibodies suggesting Graves' disease), not a primary psychiatric disorder 1, 2.
Why Current Treatment Is Failing
Sertraline and lorazepam are addressing the wrong problem. The severe anxiety symptoms are manifestations of hyperthyroidism—patients with overt hyperthyroidism frequently report anxiety, fatigue, poor concentration, and disturbed sleep, which overlap with generalized anxiety disorder 1.
Hyperthyroidism mimics panic disorder. The excess thyroid hormone causes increased heart rate, tremor, nervousness, palpitations, shortness of breath, and increased perspiration—all symptoms that can be misdiagnosed as primary anxiety or panic disorder 1, 3.
This patient's case mirrors documented misdiagnoses. A 34-year-old woman with Graves' disease was managed as panic disorder and bipolar disorder until thyroid storm developed, demonstrating how psychiatric symptoms from hyperthyroidism can be mistaken for primary psychiatric illness 3.
Immediate Treatment Protocol
Step 1: Beta-Blocker for Symptom Control (Start Today)
Propranolol is the most widely studied nonselective beta-blocker for treating increased heart rate, tremor, and nervousness in hyperthyroidism, thyroiditis, and Graves' disease 1.
Propranolol provides multiple benefits: It treats tachycardia and tremor, reverses reduced systemic vascular resistance, and inhibits peripheral conversion of T4 to the more biologically active T3 1.
Dosing: Start propranolol 20-40 mg three to four times daily, titrating based on heart rate and symptom response 1, 2.
Alternative beta-blockers: Metoprolol or atenolol can be used if propranolol is contraindicated, though propranolol has the most evidence 1.
Step 2: Antithyroid Medication (Start Immediately)
Methimazole is the preferred antithyroid drug for Graves' disease in the United States, with better efficacy and fewer side effects than propylthiouracil 2, 4, 5.
Initial dosing: Start methimazole 15-30 mg daily (depending on severity of hyperthyroidism), given as a single daily dose 2, 4, 5.
Treatment duration: Plan for 12-18 months of antithyroid drug therapy, which induces long-term remission in approximately 50% of patients with Graves' disease 4, 5.
Monitoring: Check complete blood count and liver function tests at baseline, then monitor thyroid function (TSH, free T4) every 4-6 weeks during titration 2, 5.
Step 3: Continue Sertraline But Reassess Need for Lorazepam
Continue sertraline 50 mg as it may provide benefit for residual anxiety symptoms once hyperthyroidism is controlled, and depression can coexist with thyroid disorders 1, 6.
Taper lorazepam as hyperthyroidism improves. The anxiety symptoms should dramatically improve with beta-blocker and antithyroid treatment, reducing or eliminating the need for benzodiazepines 1, 2.
Sertraline dosing is appropriate: The current 50 mg daily dose is the recommended initial therapeutic dose for anxiety disorders 6.
Confirming the Diagnosis
The lab results strongly suggest Graves' disease:
Await TSH receptor antibodies (TRAb) to definitively confirm Graves' disease, but do not delay treatment while waiting for results 1, 5.
Consider thyroid ultrasound to assess gland size and vascularity, which can help distinguish Graves' disease from other causes of hyperthyroidism 1, 5.
Critical Pitfalls to Avoid
Do not attribute all symptoms to psychiatric illness. The comorbidity between anxiety and thyroid disorders is significant, and clinical recommendations support routinely screening for thyroid disorders in patients with anxiety disorders 1.
Do not delay antithyroid treatment. Untreated hyperthyroidism can progress to thyroid storm, a life-threatening emergency that was misdiagnosed as panic attack in documented cases 3.
Monitor for agranulocytosis. Instruct the patient to immediately report fever, sore throat, or signs of infection, as methimazole can rarely cause severe neutropenia requiring drug discontinuation 2, 5.
Avoid radioactive iodine initially. While radioiodine is the treatment of choice in the United States for definitive therapy, patients should first be rendered euthyroid with antithyroid drugs to prevent thyroid storm 2, 4.
Expected Timeline for Improvement
Symptom relief from beta-blocker: Within hours to days, the patient should experience reduced heart rate, tremor, and anxiety symptoms 1, 2.
Thyroid hormone normalization: Methimazole typically reduces thyroid hormone levels within 4-6 weeks, with full symptom resolution following 2, 5.
Psychiatric symptom reassessment: Once euthyroid (typically 6-8 weeks), reassess whether anxiety symptoms persist, which would indicate a true comorbid anxiety disorder requiring continued psychiatric treatment 1.
Long-Term Management Considerations
Definitive therapy options after initial control include continued antithyroid drugs (12-18 months or longer), radioactive iodine ablation, or thyroidectomy 2, 4, 5.
Recurrence risk: Approximately 50% of patients experience recurrence after stopping antithyroid drugs, with higher risk in younger patients (<40 years), those with FT4 >40 pmol/L, and larger goiters 5.
Long-term antithyroid drug therapy (5-10 years) is feasible and associated with fewer recurrences (15%) compared to short-term treatment 5.