Successful lactation after resuming methylphenidate in a woman with narcolepsy

Abstract

Background:

New mothers with narcolepsy face difficult decisions about medications and breastfeeding in addition to the more typical challenges of becoming a parent. Scant data are available to guide these choices.

Case:

A 30-year-old gravida 1, para 1(G1P1) woman with narcolepsy with cataplexy fed her infant breastmilk for 7 months by exclusive pumping. She chose to discontinue her stimulants at delivery and restarted methylphenidate when her infant was 13 weeks old. The woman tracked milk production on an app geared toward new parents. Average daily volume was 751 ± 228 mL before and 822 ± 177 mL after restarting methylphenidate. Her infant’s growth was appropriate and did not decrease after resuming medications.

Conclusions:

In this new mother with narcolepsy, resuming methylphenidate did not reduce breastmilk volumes or negatively impact her infant. Tracking apps and other technologies can increase patients’ confidence and provide data to address gaps in medical knowledge.

Citation:

Bello G, Poirier J, Sharkey KM. Successful lactation after resuming methylphenidate in a woman with narcolepsy. J Clin Sleep Med. 2022;18(7):1891–1894.

INTRODUCTION

For individuals with narcolepsy, a chronic neurologic disorder marked by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations, it can be challenging to stay awake and engaged throughout daily activities. That challenge is compounded when the individual is a new mother adjusting to the responsibilities of providing 24-hour care for a newborn.¹ The main treatment for narcolepsy is medications, including amphetamine-based central nervous system stimulants (eg, amphetamine salts, methylphenidate), nonamphetamine stimulants (modafinil, solriamfetol, pitolisant), and oxybate salts, all of which promote daytime alertness.^2,3 Antidepressant medications that suppress rapid eye movement sleep, eg, selective serotonin reuptake inhibitor and tricyclic antidepressants, are also used to minimize cataplexy.⁴ There is minimal literature available regarding the effects of narcolepsy medications on breastfeeding with respect to infant safety, ie, behavioral and physical effects, transmission of medication into breast milk, and virtually no data regarding effects on milk production. Decisions about medication use during pregnancy and lactation are fraught with stigma and uncertainty.⁵ Despite ample data indicating that many medications can be used safely, concerns are often overstated, and better infant and child outcomes are achieved when the mother’s health is prioritized.^6–9 This knowledge gap forces expectant mothers with narcolepsy to choose whether to take their medications based on insufficient information.

The overall prevalence of methylphenidate use among women of childbearing age is low, but estimates indicate its use has been increasing in perinatal women in recent years.¹⁰ While a few small studies have demonstrated low concentrations of methylphenidate in breast milk,^10–13 the impact on milk production has not been studied. It is plausible that methylphenidate may reduce breast milk volume because it increases the concentration of extracellular dopamine in the central nervous system, which could increase activity at D2 receptors in the tuberoinfundibular pathway, and in turn, lower prolactin secretion and decrease milk supply.¹⁴ In this report, we describe a case of a new mother with narcolepsy with cataplexy who pumped exclusively and used a breastfeeding app to track milk volume and her infant’s growth from birth through 7 months.

REPORT OF CASE

A 30-year-old woman was diagnosed with narcolepsy with cataplexy at age 25 years after experiencing excessive daytime sleepiness since age 15 years when she routinely napped for 2–3 hours after school daily despite obtaining adequate sleep at night. Narcolepsy was diagnosed with a multiple sleep latency test that showed an average sleep latency of 8 minutes and 2 rapid eye movement onset naps. The patient has cataplexy when she is excessively sleepy and is particularly prone to loss of muscle tone when she experiences moments of high anxiety.

Prior to becoming pregnant, the patient was treated with armodafinil 150 mg and fluoxetine 20 mg, but her symptoms were not fully controlled on this regimen. During a discussion of alternative therapies, she expressed her plan to become pregnant and ultimately to breastfeed; thus, she was switched to methylphenidate and sertraline due to concerns about fetal exposure to armodafinil¹⁵ and because sertraline appears to confer a lower risk of fetal anomalies than other selective serotonin reuptake inhibitors¹⁶ and also has low transmission into breast milk.¹⁷ She was at a stable dose of methylphenidate controlled release (CR) 54 mg, methylphenidate 20 mg, and sertraline 100 mg when she became pregnant. Although she did not meet criteria for hyperemesis gravidarum, she experienced significant nausea and vomiting and discontinued methylphenidate ∼5 weeks gestation. She continued the sertraline at 100 mg and was prescribed vitamin B6 and doxylamine 100 mg (which was noted to worsen excessive daytime sleepiness).

At 21 weeks’ gestation, she chose to resume methylphenidate CR 36 mg each morning and methylphenidate 5 mg twice daily because of excessive daytime sleepiness and frequent cataplexy attacks. On this combination, her narcolepsy symptoms were only partially controlled, requiring 2- to 4-hour naps daily to combat irresistible sleepiness. At 28 weeks’ gestation, she discontinued the methylphenidate CR because she was experiencing difficulty falling asleep at night. This sleep-onset insomnia was attributed to multiple factors, including her irregular sleep-wake pattern, long periods of daytime sleep due to the antihistamine effects of doxylamine, and worsening symptoms of gastroesophageal reflux and intrahepatic cholestasis of pregnancy (treated with ursodiol 300 mg twice daily). In the last several weeks of her pregnancy, she managed her sleepiness with 10–15 mg of methylphenidate daily.

The patient was induced at 36 and 5/7 weeks’ gestation because of concerns related to cholestasis of pregnancy and delivered a healthy infant via vaginal delivery. At delivery, she discontinued her stimulants and took only sertraline 100 mg and a prenatal vitamin. When her infant was 13 weeks old, she resumed methylphenidate 10 mg 3 times a day because her sleepiness was becoming debilitating. She had also started having more frequent and more severe cataplexy episodes, which were frightening and had the potential to put her infant at risk. At postpartum week 14, she increased methylphenidate 10 mg frequency to 4 times a day and at 22 weeks’ postpartum, she resumed methylphenidate CR at 36 mg each morning. The patient’s narcolepsy symptoms improved significantly after she restarted her medications.

At the time of delivery, the mother and infant struggled to initiate breastfeeding. The patient was committed to feeding her infant with breastmilk and began expressing breastmilk for bottle feeding at birth. Her infant was fed breastmilk exclusively until 6 months of age and was weaned at 7 months. She tracked her breastmilk volumes daily at each pumping session using a free smartphone app, “Baby Tracker,” allowing her to record the time she spent pumping and the volumes pumped from each breast per session. She measured her breastmilk output in milliliters based on the bottle measurement and confirmed by breastmilk storage bags. Her engagement with this health monitoring app intended for new parents provided the opportunity for us to assess whether her milk supply was affected by resuming her medications.

The patient pumped for 199 days postdelivery, and volumes were available for 48 days before and 115 days after restarting methylphenidate. (There were 36 missing days during the period when her narcolepsy symptoms were worsening, and she took a break from entering data in the app.) She stopped breastfeeding when her infant was 7 months old because she had met her breastfeeding goals. As shown in Figure 1, breastmilk volumes did not decrease after resuming methylphenidate at 13 weeks postpartum. For example, average daily volume was 751 ± 228 mL during the 48 days before restarting methylphenidate and 822 ± 177 mL after restarting. The average volume per pump during weeks 6–8 (the last 3 weeks before resuming methylphenidate for which data were recorded) was 230.1 ± 25.0 mL, which did not differ significantly from the volume per pump during the first 3 weeks after restarting methylphenidate: 243.4 ± 32.9 mL (weeks 13–15; t = 1.4755, df = 40, P = ns). Moreover, her infant has continued to thrive and has met all milestones appropriately. Infant weight and length are shown in Figure 2.

Figure 1. Average breastmilk volume pumped per day before (purple) and after (yellow) restarting methylphenidate (left y-axis).

Black bars represent mean volume per pumping session averaged by week (right y-axis). The rise in breastmilk to meet the infant’s increasing needs in the first few weeks of life and the decreased production while weaning is also evident.

Figure 2. Infant growth from 0 to 6 months.

Length and weight measures were normal before and after the patient restarted methylphenidate.

DISCUSSION

Narcolepsy is a chronic neurological condition characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. Women diagnosed with narcolepsy with cataplexy face numerous challenges during the postpartum period, including concerns about whether they will be alert enough during the day and able to wake up at night to care for their infant and about possibly injuring their baby during a cataplexy episode. These worries are compounded by the scarcity of information regarding the effects of medications on the infant, transmission of medication through breastmilk, and impact on successful lactation. Apprehension about disease management and infant wellbeing may play a role in whether women with narcolepsy decide to bear children,¹ and may also contribute to the later age at which they become parents.⁶

In our case report, we describe a patient who successfully fed her newborn with breastmilk before and after taking methylphenidate at her prior therapeutic dose of 20–30 mg. Based on the mechanism of action of methylphenidate, one plausible risk of restarting the medication was a decrease in breastmilk volume.¹⁴ However, in addition to feeling less sleepy and experiencing fewer cataplexy events, the patient did not experience a decrease in milk production after restarting medication.

Methylphenidate has a relatively low molecular weight and is freely soluble in water, allowing for transmission from the maternal circulation to breastmilk.¹⁰ Nevertheless, likely due to its short half-life (1.4 to 4.2 hours) and the relatively low plasma levels produced by immediate-release preparations, methylphenidate concentrations in breastmilk and subsequent infant exposures are low. For instance, in a study of 3 lactating women taking between 35 and 80 mg of methylphenidate (average dose = 52 mg), the mean concentration of methylphenidate in breastmilk was 19 ± 9.2 μg/L, yielding an absolute infant dose of 2.9 ± 1.4 μg/kg/day.¹³ Thus, on average, the infants received a relative dose that was less than 1% of the maternal dose. In our case, resuming methylphenidate had no apparent negative effects on the infant, who was sleeping, eating, and gaining weight normally at every pediatric evaluation.

These results/observations provide insight to treatment plans that can be used with other breastfeeding patients diagnosed with narcolepsy. Furthermore, methylphenidate is prescribed commonly to women with attention deficit/hyperactivity disorder and thus this outcome may be relevant and help guide treatment decisions in that population as well.¹⁸ We note that the patient did not restart her medications until 13 weeks after delivery, which may have allowed her to establish an adequate milk supply. It is possible that methylphenidate may have affected her lactation differently earlier in her breastfeeding course. Given the value placed on breastfeeding, more work is needed to understand the effects of medications on milk production.

In addition to providing reassuring data about lactation, this case highlights the important contributions that patients can make to our medical knowledge. Self-monitoring and baby monitoring apps are common and may help new parents feel a sense of control as they adjust to their new roles.¹⁹ Thus, future research should focus on the use of health tracking apps and the insights that can be gleaned from patients’ personal data to tailor treatment plans.

CONCLUSIONS

Women with narcolepsy with cataplexy face specific challenges during the postpartum period, including the dearth of information regarding the effects of medications on the infant, transmission of medication through breastmilk, and the impact of narcolepsy symptoms and medications on successful lactation.

Methylphenidate (Ritalin) is a stimulant that is used commonly in patients with narcolepsy and has relatively low transmission in breastmilk. Its mechanism of action is blockade of the dopamine transporter resulting in a rise of extracellular dopamine. Prolactin release can be inhibited by elevated dopamine levels, and therefore there is a possibility that methylphenidate could suppress lactation.

We describe a case of successful feeding with breastmilk in a woman with narcolepsy with cataplexy. She pumped exclusively and used a tracking app, allowing us to observe that resuming methylphenidate at postpartum week 13 did not decrease milk production.

Methylphenidate has relatively low transmission from maternal plasma to breastmilk, and although there are few studies measuring methylphenidate levels in infants, existing data indicate that infants exposed to methylphenidate in breastmilk receive less than 1% of the maternal dose.

Digital innovations can help clinicians deliver personalized care and also provide an opportunity for data collection to enhance our medical knowledge.

DISCLOSURE STATEMENT

All authors have seen and approved this manuscript. KMS receives research support from R01MH118269 and U54GM115677. The authors report no conflicts of interest.