Adderall XR and SSRIs (Sertraline, Escitalopram): Interaction Risk, Monitoring, and Safety

Is Adderall XR safe to combine with sertraline or escitalopram?

Neither label lists the other drug as a contraindication. Zoloft is contraindicated in people taking MAOIs or pimozide and in those with a known sertraline hypersensitivity [1]. The Adderall XR label contraindicates the product in people with a known hypersensitivity to amphetamine or another component, and in people taking an MAOI or within 14 days of stopping one, including linezolid and intravenous methylene blue, because of hypertensive crisis [2].

The labels do address the pairing, from two directions. Both name the other drug class as a serotonin syndrome risk [1][2], and the Adderall XR label adds a metabolic route: CYP2D6 inhibitors may increase amphetamine exposure [2]. Those are separate concerns.

What each label says about serotonin syndrome

The Zoloft label lists amphetamines among the drugs that raise serotonin syndrome risk, alongside triptans, tricyclics, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone and St. John's wort [1]. It also notes the syndrome can occur with Zoloft alone. The label says to monitor all patients on Zoloft and, when another serotonergic drug is clinically warranted, to inform patients of the increased risk and monitor for symptoms [1]. A separate interaction table in the same label says to monitor particularly during treatment initiation and dose increases [1].

The Adderall XR prescribing information says to start with lower doses and monitor, especially at initiation and after dose increases, when amphetamine is combined with serotonergic drugs or CYP2D6 inhibitors; it also says to stop both drugs if serotonin syndrome occurs [2].

What serotonin syndrome looks like

The Zoloft label describes it as a potentially life-threatening condition with mental status changes (agitation, hallucinations, delirium, coma), autonomic instability (tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular findings (tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures and gastrointestinal symptoms such as nausea, vomiting and diarrhea [1]. The label says to discontinue Zoloft and any other serotonergic drug immediately and begin supportive symptomatic treatment if these symptoms appear [1].

Does sertraline or escitalopram raise amphetamine levels?

The Adderall XR label states that CYP2D6 is involved in forming 4-hydroxyamphetamine, a metabolite of amphetamine, and that CYP2D6 inhibitors may increase amphetamine exposure and the risk of serotonin syndrome [2]. That passage names no particular inhibitors and gives no figure for either SSRI [2].

Both SSRIs touch CYP2D6 to some degree:

• Sertraline. The Zoloft label lists the drug as a CYP2D6 inhibitor and says the dose of a CYP2D6 substrate may need to be decreased with Zoloft, and increased again if Zoloft is stopped; the effect is less prominent at lower sertraline doses [1].
• Escitalopram. At 20 mg per day for 21 days, escitalopram raised desipramine AUC by 100% and peak concentration by 40%, and raised metoprolol AUC by 82% and peak by 50% [3]. Those are CYP2D6 probe drugs, not amphetamine.

For comparison, the FDA's drug interaction table lists fluoxetine and paroxetine as strong CYP2D6 inhibitors [4].

Sertraline or escitalopram: is one clearly preferable?

Neither label ranks the two for this interaction. Escitalopram at its 20 mg maximum doubled desipramine exposure [3], and sertraline's label identifies it as a CYP2D6 inhibitor without a potency figure [1].

Their approved uses differ. Zoloft is approved for major depressive disorder, OCD, panic disorder, PTSD, social anxiety disorder and premenstrual dysphoric disorder [1]. Lexapro is approved for major depressive disorder from age 12 and generalized anxiety disorder from age 7 [3]. Those indications say nothing about which has a lower Adderall XR interaction risk.

What the labels flag for the combination

• Heart rate and blood pressure. The Adderall XR label says CNS stimulants raise blood pressure (mean about 2 to 4 mm Hg) and heart rate (mean about 3 to 6 bpm), with larger rises in some people, and says to monitor [2].
• Serotonin symptoms. Both labels say to watch for these, particularly at initiation and after dose increases [1][2].
• QT interval. The Zoloft label says to use caution in patients with risk factors for QTc prolongation and to avoid drugs known to prolong QTc [1]. The Lexapro label's warnings section contains no QT warning; its QT data sit in the pharmacology, adverse reaction and overdose sections, including a thorough QT study of 113 people showing a 4.5 ms rise at 10 mg and a 10.7 ms rise at 30 mg, with a predicted 6.6 ms at 20 mg [3].

Side effects that overlap

Both drugs cause appetite and sleep effects in their trials. In Zoloft's pooled placebo-controlled trials, decreased appetite occurred in 7% versus 2% on placebo and insomnia in 20% versus 13% [1]. In the Adderall XR adult trial, loss of appetite occurred in 33% versus 3% and insomnia in 27% versus 13% [2].

Adolescents and older adults

SSRIs carry a boxed warning for suicidal thoughts and behaviors in pediatric and young adult patients. In the Zoloft label's pooled analysis, the drug-placebo difference was 14 additional cases per 1,000 treated under age 18 and 5 additional cases at ages 18 to 24, with 1 fewer case at ages 25 to 64 and 6 fewer at 65 and older [1]. The Adderall XR label says it is not recommended under age 6 because of higher plasma exposure and more adverse reactions such as weight loss [2]. In older adults, the recommended escitalopram dose for most people is 10 mg once daily [3]. The Adderall XR label advises avoiding stimulants in people with structural cardiac abnormalities, cardiomyopathy, serious arrhythmia, coronary artery disease or other serious cardiac disease [2].